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* memory-failure: use num_poisoned_pages instead of mce_bad_pagesXishi Qiu2013-02-23
| | | | | | | | | | | | | | Since MCE is an x86 concept, and this code is in mm/, it would be better to use the name num_poisoned_pages instead of mce_bad_pages. [akpm@linux-foundation.org: fix mm/sparse.c] Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Suggested-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: consider compound pages when free memmapWen Congyang2013-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | usemap could also be allocated as compound pages. Should also consider compound pages when freeing memmap. If we don't fix it, there could be problems when we free vmemmap pagetables which are stored in compound pages. The old pagetables will not be freed properly, and when we add the memory again, no new pagetable will be created. And the old pagetable entry is used, than the kernel will panic. The call trace is like the following: BUG: unable to handle kernel paging request at ffffea0040000000 IP: [<ffffffff816a483f>] sparse_add_one_section+0xef/0x166 PGD 7ff7d4067 PUD 78e035067 PMD 78e11d067 PTE 0 Oops: 0002 [#1] SMP Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle iptable_filter ip_tables bridge stp llc sunrpc binfmt_misc dm_mirror dm_region_hash dm_log dm_mod vhost_net macvtap macvlan tun uinput iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm crc32c_intel microcode pcspkr sg lpc_ich mfd_core i2c_i801 i2c_core i7core_edac edac_core ioatdma e1000e igb dca ptp pps_core sd_mod crc_t10dif megaraid_sas mptsas mptscsih mptbase scsi_transport_sas scsi_mod CPU 0 Pid: 4, comm: kworker/0:0 Tainted: G W 3.8.0-rc3-phy-hot-remove+ #3 FUJITSU-SV PRIMEQUEST 1800E/SB RIP: 0010:[<ffffffff816a483f>] [<ffffffff816a483f>] sparse_add_one_section+0xef/0x166 RSP: 0018:ffff8807bdcb35d8 EFLAGS: 00010006 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000200000 RDX: ffff88078df01148 RSI: 0000000000000282 RDI: ffffea0040000000 RBP: ffff8807bdcb3618 R08: 4cf05005b019467a R09: 0cd98fa09631467a R10: 0000000000000000 R11: 0000000000030e20 R12: 0000000000008000 R13: ffffea0040000000 R14: ffff88078df66248 R15: ffff88078ea13b10 FS: 0000000000000000(0000) GS:ffff8807c1a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffffea0040000000 CR3: 0000000001c0c000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kworker/0:0 (pid: 4, threadinfo ffff8807bdcb2000, task ffff8807bde18000) Call Trace: __add_pages+0x85/0x120 arch_add_memory+0x71/0xf0 add_memory+0xd6/0x1f0 acpi_memory_device_add+0x170/0x20c acpi_device_probe+0x50/0x18a really_probe+0x6c/0x320 driver_probe_device+0x47/0xa0 __device_attach+0x53/0x60 bus_for_each_drv+0x6c/0xa0 device_attach+0xa8/0xc0 bus_probe_device+0xb0/0xe0 device_add+0x301/0x570 device_register+0x1e/0x30 acpi_device_register+0x1d8/0x27c acpi_add_single_object+0x1df/0x2b9 acpi_bus_check_add+0x112/0x18f acpi_ns_walk_namespace+0x105/0x255 acpi_walk_namespace+0xcf/0x118 acpi_bus_scan+0x5b/0x7c acpi_bus_add+0x2a/0x2c container_notify_cb+0x112/0x1a9 acpi_ev_notify_dispatch+0x46/0x61 acpi_os_execute_deferred+0x27/0x34 process_one_work+0x20e/0x5c0 worker_thread+0x12e/0x370 kthread+0xee/0x100 ret_from_fork+0x7c/0xb0 Code: 00 00 48 89 df 48 89 45 c8 e8 3e 71 b1 ff 48 89 c2 48 8b 75 c8 b8 ef ff ff ff f6 02 01 75 4b 49 63 cc 31 c0 4c 89 ef 48 c1 e1 06 <f3> aa 48 8b 02 48 83 c8 01 48 85 d2 48 89 02 74 29 a8 01 74 25 RIP [<ffffffff816a483f>] sparse_add_one_section+0xef/0x166 RSP <ffff8807bdcb35d8> CR2: ffffea0040000000 ---[ end trace e7f94e3a34c442d4 ]--- Kernel panic - not syncing: Fatal exception Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: remove memmap of sparse-vmemmapTang Chen2013-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new API vmemmap_free() to free and remove vmemmap pagetables. Since pagetable implements are different, each architecture has to provide its own version of vmemmap_free(), just like vmemmap_populate(). Note: vmemmap_free() is not implemented for ia64, ppc, s390, and sparc. [mhocko@suse.cz: fix implicit declaration of remove_pagetable] Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: move pgdat_resize_lock into sparse_remove_one_section()Tang Chen2013-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In __remove_section(), we locked pgdat_resize_lock when calling sparse_remove_one_section(). This lock will disable irq. But we don't need to lock the whole function. If we do some work to free pagetables in free_section_usemap(), we need to call flush_tlb_all(), which need irq enabled. Otherwise the WARN_ON_ONCE() in smp_call_function_many() will be triggered. If we lock the whole sparse_remove_one_section(), then we come to this call trace: ------------[ cut here ]------------ WARNING: at kernel/smp.c:461 smp_call_function_many+0xbd/0x260() Hardware name: PRIMEQUEST 1800E ...... Call Trace: smp_call_function_many+0xbd/0x260 smp_call_function+0x3b/0x50 on_each_cpu+0x3b/0xc0 flush_tlb_all+0x1c/0x20 remove_pagetable+0x14e/0x1d0 vmemmap_free+0x18/0x20 sparse_remove_one_section+0xf7/0x100 __remove_section+0xa2/0xb0 __remove_pages+0xa0/0xd0 arch_remove_memory+0x6b/0xc0 remove_memory+0xb8/0xf0 acpi_memory_device_remove+0x53/0x96 acpi_device_remove+0x90/0xb2 __device_release_driver+0x7c/0xf0 device_release_driver+0x2f/0x50 acpi_bus_remove+0x32/0x6d acpi_bus_trim+0x91/0x102 acpi_bus_hot_remove_device+0x88/0x16b acpi_os_execute_deferred+0x27/0x34 process_one_work+0x20e/0x5c0 worker_thread+0x12e/0x370 kthread+0xee/0x100 ret_from_fork+0x7c/0xb0 ---[ end trace 25e85300f542aa01 ]--- Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug, mm/sparse.c: clear the memory to store struct pageWen Congyang2012-12-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If sparse memory vmemmap is enabled, we can't free the memory to store struct page when a memory device is hotremoved, because we may store struct page in the memory to manage the memory which doesn't belong to this memory device. When we hotadded this memory device again, we will reuse this memory to store struct page, and struct page may contain some obsolete information, and we will get bad-page state: init_memory_mapping: [mem 0x80000000-0x9fffffff] Built 2 zonelists in Node order, mobility grouping on. Total pages: 547617 Policy zone: Normal BUG: Bad page state in process bash pfn:9b6dc page:ffffea0002200020 count:0 mapcount:0 mapping: (null) index:0xfdfdfdfdfdfdfdfd page flags: 0x2fdfdfdfd5df9fd(locked|referenced|uptodate|dirty|lru|active|slab|owner_priv_1|private|private_2|writeback|head|tail|swapcache|reclaim|swapbacked|unevictable|uncached|compound_lock) Modules linked in: netconsole acpiphp pci_hotplug acpi_memhotplug loop kvm_amd kvm microcode tpm_tis tpm tpm_bios evdev psmouse serio_raw i2c_piix4 i2c_core parport_pc parport processor button thermal_sys ext3 jbd mbcache sg sr_mod cdrom ata_generic virtio_net ata_piix virtio_blk libata virtio_pci virtio_ring virtio scsi_mod Pid: 988, comm: bash Not tainted 3.6.0-rc7-guest #12 Call Trace: [<ffffffff810e9b30>] ? bad_page+0xb0/0x100 [<ffffffff810ea4c3>] ? free_pages_prepare+0xb3/0x100 [<ffffffff810ea668>] ? free_hot_cold_page+0x48/0x1a0 [<ffffffff8112cc08>] ? online_pages_range+0x68/0xa0 [<ffffffff8112cba0>] ? __online_page_increment_counters+0x10/0x10 [<ffffffff81045561>] ? walk_system_ram_range+0x101/0x110 [<ffffffff814c4f95>] ? online_pages+0x1a5/0x2b0 [<ffffffff8135663d>] ? __memory_block_change_state+0x20d/0x270 [<ffffffff81356756>] ? store_mem_state+0xb6/0xf0 [<ffffffff8119e482>] ? sysfs_write_file+0xd2/0x160 [<ffffffff8113769a>] ? vfs_write+0xaa/0x160 [<ffffffff81137977>] ? sys_write+0x47/0x90 [<ffffffff814e2f25>] ? async_page_fault+0x25/0x30 [<ffffffff814ea239>] ? system_call_fastpath+0x16/0x1b Disabling lock debugging due to kernel taint This patch clears the memory to store struct page to avoid unexpected error. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Minchan Kim <minchan.kim@gmail.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reported-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: update mce_bad_pages when removing the memoryWen Congyang2012-12-11
| | | | | | | | | | | | | | | | | | | | | When we hotremove a memory device, we will free the memory to store struct page. If the page is hwpoisoned page, we should decrease mce_bad_pages. [akpm@linux-foundation.org: cleanup ifdefs] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/vmemmap: fix wrong use of virt_to_pageJianguo Wu2012-11-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I enable CONFIG_DEBUG_VIRTUAL and CONFIG_SPARSEMEM_VMEMMAP, when doing memory hotremove, there is a kernel BUG at arch/x86/mm/physaddr.c:20. It is caused by free_section_usemap()->virt_to_page(), virt_to_page() is only used for kernel direct mapping address, but sparse-vmemmap uses vmemmap address, so it is going wrong here. ------------[ cut here ]------------ kernel BUG at arch/x86/mm/physaddr.c:20! invalid opcode: 0000 [#1] SMP Modules linked in: acpihp_drv acpihp_slot edd cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse vfat fat loop dm_mod coretemp kvm crc32c_intel ipv6 ixgbe igb iTCO_wdt i7core_edac edac_core pcspkr iTCO_vendor_support ioatdma microcode joydev sr_mod i2c_i801 dca lpc_ich mfd_core mdio tpm_tis i2c_core hid_generic tpm cdrom sg tpm_bios rtc_cmos button ext3 jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif processor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc scsi_dh ata_generic ata_piix libata megaraid_sas scsi_mod CPU 39 Pid: 6454, comm: sh Not tainted 3.7.0-rc1-acpihp-final+ #45 QCI QSSC-S4R/QSSC-S4R RIP: 0010:[<ffffffff8103c908>] [<ffffffff8103c908>] __phys_addr+0x88/0x90 RSP: 0018:ffff8804440d7c08 EFLAGS: 00010006 RAX: 0000000000000006 RBX: ffffea0012000000 RCX: 000000000000002c ... Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Reviewd-by: Wen Congyang <wency@cn.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse: remove index_init_lockGavin Shan2012-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sparse_index_init() uses the index_init_lock spinlock to protect root mem_section assignment. The lock is not necessary anymore because the function is called only during boot (during paging init which is executed only from a single CPU) and from the hotplug code (by add_memory() via arch_add_memory()) which uses mem_hotplug_mutex. The lock was introduced by 28ae55c9 ("sparsemem extreme: hotplug preparation") and sparse_index_init() was used only during boot at that time. Later when the hotplug code (and add_memory()) was introduced there was no synchronization so it was possible to online more sections from the same root probably (though I am not 100% sure about that). The first synchronization has been added by 6ad696d2 ("mm: allow memory hotplug and hibernation in the same kernel") which was later replaced by the mem_hotplug_mutex - 20d6c96b ("mem-hotplug: introduce {un}lock_memory_hotplug()"). Let's remove the lock as it is not needed and it makes the code more confusing. [mhocko@suse.cz: changelog] Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse: more checks on mem_section numberGavin Shan2012-07-31
| | | | | | | | | | | | | __section_nr() was implemented to retrieve the corresponding memory section number according to its descriptor. It's possible that the specified memory section descriptor doesn't exist in the global array. So add more checking on that and report an error for a wrong case. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse: optimize sparse_index_allocGavin Shan2012-07-31
| | | | | | | | | | | | | With CONFIG_SPARSEMEM_EXTREME, the two levels of memory section descriptors are allocated from slab or bootmem. When allocating from slab, let slab/bootmem allocator clear the memory chunk. We needn't clear it explicitly. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: setup pageblock_order before it's used by sparsememXishi Qiu2012-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On architectures with CONFIG_HUGETLB_PAGE_SIZE_VARIABLE set, such as Itanium, pageblock_order is a variable with default value of 0. It's set to the right value by set_pageblock_order() in function free_area_init_core(). But pageblock_order may be used by sparse_init() before free_area_init_core() is called along path: sparse_init() ->sparse_early_usemaps_alloc_node() ->usemap_size() ->SECTION_BLOCKFLAGS_BITS ->((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) The uninitialized pageblock_size will cause memory wasting because usemap_size() returns a much bigger value then it's really needed. For example, on an Itanium platform, sparse_init() pageblock_order=0 usemap_size=24576 free_area_init_core() before pageblock_order=0, usemap_size=24576 free_area_init_core() after pageblock_order=12, usemap_size=8 That means 24K memory has been wasted for each section, so fix it by calling set_pageblock_order() from sparse_init(). Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Keping Chen <chenkeping@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: sparse: fix usemap allocation above node descriptor sectionYinghai Lu2012-07-11
| | | | | | | | | | | | | | | | | | | | | | | | After commit f5bf18fa22f8 ("bootmem/sparsemem: remove limit constraint in alloc_bootmem_section"), usemap allocations may easily be placed outside the optimal section that holds the node descriptor, even if there is space available in that section. This results in unnecessary hotplug dependencies that need to have the node unplugged before the section holding the usemap. The reason is that the bootmem allocator doesn't guarantee a linear search starting from the passed allocation goal but may start out at a much higher address absent an upper limit. Fix this by trying the allocation with the limit at the section end, then retry without if that fails. This keeps the fix from f5bf18fa22f8 of not panicking if the allocation does not fit in the section, but still makes sure to try to stay within the section at first. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.3.x, 3.4.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: sparse: fix section usemap placement calculationYinghai Lu2012-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 238305bb4d41 ("mm: remove sparsemem allocation details from the bootmem allocator") introduced a bug in the allocation goal calculation that put section usemaps not in the same section as the node descriptors, creating unnecessary hotplug dependencies between them: node 0 must be removed before remove section 16399 node 1 must be removed before remove section 16399 node 2 must be removed before remove section 16399 node 3 must be removed before remove section 16399 node 4 must be removed before remove section 16399 node 5 must be removed before remove section 16399 node 6 must be removed before remove section 16399 The reason is that it applies PAGE_SECTION_MASK to the physical address of the node descriptor when finding a suitable place to put the usemap, when this mask is actually intended to be used with PFNs. Because the PFN mask is wider, the target address will point beyond the wanted section holding the node descriptor and the node must be offlined before the section holding the usemap can go. Fix this by extending the mask to address width before use. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove sparsemem allocation details from the bootmem allocatorJohannes Weiner2012-05-29
| | | | | | | | | | | | | | | | | | | alloc_bootmem_section() derives allocation area constraints from the specified sparsemem section. This is a bit specific for a generic memory allocator like bootmem, though, so move it over to sparsemem. As __alloc_bootmem_node_nopanic() already retries failed allocations with relaxed area constraints, the fallback code in sparsemem.c can be removed and the code becomes a bit more compact overall. [akpm@linux-foundation.org: fix build] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bootmem/sparsemem: remove limit constraint in alloc_bootmem_sectionNishanth Aravamudan2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While testing AMS (Active Memory Sharing) / CMO (Cooperative Memory Overcommit) on powerpc, we tripped the following: kernel BUG at mm/bootmem.c:483! cpu 0x0: Vector: 700 (Program Check) at [c000000000c03940] pc: c000000000a62bd8: .alloc_bootmem_core+0x90/0x39c lr: c000000000a64bcc: .sparse_early_usemaps_alloc_node+0x84/0x29c sp: c000000000c03bc0 msr: 8000000000021032 current = 0xc000000000b0cce0 paca = 0xc000000001d80000 pid = 0, comm = swapper kernel BUG at mm/bootmem.c:483! enter ? for help [c000000000c03c80] c000000000a64bcc .sparse_early_usemaps_alloc_node+0x84/0x29c [c000000000c03d50] c000000000a64f10 .sparse_init+0x12c/0x28c [c000000000c03e20] c000000000a474f4 .setup_arch+0x20c/0x294 [c000000000c03ee0] c000000000a4079c .start_kernel+0xb4/0x460 [c000000000c03f90] c000000000009670 .start_here_common+0x1c/0x2c This is BUG_ON(limit && goal + size > limit); and after some debugging, it seems that goal = 0x7ffff000000 limit = 0x80000000000 and sparse_early_usemaps_alloc_node -> sparse_early_usemaps_alloc_pgdat_section calls return alloc_bootmem_section(usemap_size() * count, section_nr); This is on a system with 8TB available via the AMS pool, and as a quirk of AMS in firmware, all of that memory shows up in node 0. So, we end up with an allocation that will fail the goal/limit constraints. In theory, we could "fall-back" to alloc_bootmem_node() in sparse_early_usemaps_alloc_node(), but since we actually have HOTREMOVE defined, we'll BUG_ON() instead. A simple solution appears to be to unconditionally remove the limit condition in alloc_bootmem_section, meaning allocations are allowed to cross section boundaries (necessary for systems of this size). Johannes Weiner pointed out that if alloc_bootmem_section() no longer guarantees section-locality, we need check_usemap_section_nr() to print possible cross-dependencies between node descriptors and the usemaps allocated through it. That makes the two loops in sparse_early_usemaps_alloc_node() identical, so re-factor the code a bit. [akpm@linux-foundation.org: code simplification] Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Anton Blanchard <anton@au1.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> [3.3.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Map most files to use export.h instead of module.hPaul Gortmaker2011-10-31
| | | | | | | | The files changed within are only using the EXPORT_SYMBOL macro variants. They are not using core modular infrastructure and hence don't need module.h but only the export.h header. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* mm: make some struct page's constIan Campbell2011-07-25
| | | | | | | | | | | | | | These uses are read-only and in a subsequent patch I have a const struct page in my hand... [akpm@linux-foundation.org: fix warnings in lowmem_page_address()] Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix common misspellingsLucas De Marchi2011-03-31
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* thp: remove PG_buddyAndrea Arcangeli2011-01-13
| | | | | | | | | | | | | | PG_buddy can be converted to _mapcount == -2. So the PG_compound_lock can be added to page->flags without overflowing (because of the sparse section bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y. This also has to move the memory hotplug code from _mapcount to lru.next to avoid any risk of clashes. We can't use lru.next for PG_buddy removal, but memory hotplug can use lru.next even more easily than the mapcount instead. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparsemem: on no vmemmap path put mem_map on node high tooYinghai Lu2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to put mem_map high when virtual memmap is not used. before this patch free mem pfn range on first node: [ 0.000000] 19 - 1f [ 0.000000] 28 40 - 80 95 [ 0.000000] 702 740 - 1000 1000 [ 0.000000] 347c - 347e [ 0.000000] 34e7 3500 - 3b80 3b8b [ 0.000000] 73b8b 73bc0 - 73c00 73c00 [ 0.000000] 73ddd - 73e00 [ 0.000000] 73fdd - 74000 [ 0.000000] 741dd - 74200 [ 0.000000] 743dd - 74400 [ 0.000000] 745dd - 74600 [ 0.000000] 747dd - 74800 [ 0.000000] 749dd - 74a00 [ 0.000000] 74bdd - 74c00 [ 0.000000] 74ddd - 74e00 [ 0.000000] 74fdd - 75000 [ 0.000000] 751dd - 75200 [ 0.000000] 753dd - 75400 [ 0.000000] 755dd - 75600 [ 0.000000] 757dd - 75800 [ 0.000000] 759dd - 75a00 [ 0.000000] 79bdd 79c00 - 7d540 7d550 [ 0.000000] 7f745 - 7f750 [ 0.000000] 10000b 100040 - 2080000 2080000 so only 79c00 - 7d540 are major free block under 4g... after this patch, we will get [ 0.000000] 19 - 1f [ 0.000000] 28 40 - 80 95 [ 0.000000] 702 740 - 1000 1000 [ 0.000000] 347c - 347e [ 0.000000] 34e7 3500 - 3600 3600 [ 0.000000] 37dd - 3800 [ 0.000000] 39dd - 3a00 [ 0.000000] 3bdd - 3c00 [ 0.000000] 3ddd - 3e00 [ 0.000000] 3fdd - 4000 [ 0.000000] 41dd - 4200 [ 0.000000] 43dd - 4400 [ 0.000000] 45dd - 4600 [ 0.000000] 47dd - 4800 [ 0.000000] 49dd - 4a00 [ 0.000000] 4bdd - 4c00 [ 0.000000] 4ddd - 4e00 [ 0.000000] 4fdd - 5000 [ 0.000000] 51dd - 5200 [ 0.000000] 53dd - 5400 [ 0.000000] 95dd 9600 - 7d540 7d550 [ 0.000000] 7f745 - 7f750 [ 0.000000] 17000b 170040 - 2080000 2080000 we will have 9600 - 7d540 for major free block... sparse-vmemmap path already used __alloc_bootmem_node_high() Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* sparsemem: Fix compilation on PowerPCYinghai Lu2010-03-01
| | | | | | | | | | | | | | | | | | | | | | | | | Stephen reported: build (powerpc ppc64_defconfig) produced these warnings: mm/sparse.c: In function 'sparse_init': mm/sparse.c:488: warning: unused variable 'map_count' mm/sparse.c:484: warning: unused variable 'size2' mm/sparse.c:481: warning: unused variable 'map_map' mm/sparse.c: At top level: mm/sparse.c:442: warning: 'sparse_early_mem_maps_alloc_node' defined but not used Introduced by commit 9bdac914240759457175ac0d6529a37d2820bc4d ("sparsemem: Put mem map for one node together"). Conditionalize the bits appropriately based on the setting of CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <4B895682.1080706@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* sparsemem: Put mem map for one node together.Yinghai Lu2010-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add vmemmap_alloc_block_buf for mem map only. It will fallback to the old way if it cannot get a block that big. Before this patch, when a node have 128g ram installed, memmap are split into two parts or more. [ 0.000000] [ffffea0000000000-ffffea003fffffff] PMD -> [ffff880100600000-ffff88013e9fffff] on node 1 [ 0.000000] [ffffea0040000000-ffffea006fffffff] PMD -> [ffff88013ec00000-ffff88016ebfffff] on node 1 [ 0.000000] [ffffea0070000000-ffffea007fffffff] PMD -> [ffff882000600000-ffff8820105fffff] on node 0 [ 0.000000] [ffffea0080000000-ffffea00bfffffff] PMD -> [ffff882010800000-ffff8820507fffff] on node 0 [ 0.000000] [ffffea00c0000000-ffffea00dfffffff] PMD -> [ffff882050a00000-ffff8820709fffff] on node 0 [ 0.000000] [ffffea00e0000000-ffffea00ffffffff] PMD -> [ffff884000600000-ffff8840205fffff] on node 2 [ 0.000000] [ffffea0100000000-ffffea013fffffff] PMD -> [ffff884020800000-ffff8840607fffff] on node 2 [ 0.000000] [ffffea0140000000-ffffea014fffffff] PMD -> [ffff884060a00000-ffff8840709fffff] on node 2 [ 0.000000] [ffffea0150000000-ffffea017fffffff] PMD -> [ffff886000600000-ffff8860305fffff] on node 3 [ 0.000000] [ffffea0180000000-ffffea01bfffffff] PMD -> [ffff886030800000-ffff8860707fffff] on node 3 [ 0.000000] [ffffea01c0000000-ffffea01ffffffff] PMD -> [ffff888000600000-ffff8880405fffff] on node 4 [ 0.000000] [ffffea0200000000-ffffea022fffffff] PMD -> [ffff888040800000-ffff8880707fffff] on node 4 [ 0.000000] [ffffea0230000000-ffffea023fffffff] PMD -> [ffff88a000600000-ffff88a0105fffff] on node 5 [ 0.000000] [ffffea0240000000-ffffea027fffffff] PMD -> [ffff88a010800000-ffff88a0507fffff] on node 5 [ 0.000000] [ffffea0280000000-ffffea029fffffff] PMD -> [ffff88a050a00000-ffff88a0709fffff] on node 5 [ 0.000000] [ffffea02a0000000-ffffea02bfffffff] PMD -> [ffff88c000600000-ffff88c0205fffff] on node 6 [ 0.000000] [ffffea02c0000000-ffffea02ffffffff] PMD -> [ffff88c020800000-ffff88c0607fffff] on node 6 [ 0.000000] [ffffea0300000000-ffffea030fffffff] PMD -> [ffff88c060a00000-ffff88c0709fffff] on node 6 [ 0.000000] [ffffea0310000000-ffffea033fffffff] PMD -> [ffff88e000600000-ffff88e0305fffff] on node 7 [ 0.000000] [ffffea0340000000-ffffea037fffffff] PMD -> [ffff88e030800000-ffff88e0707fffff] on node 7 after patch will get [ 0.000000] [ffffea0000000000-ffffea006fffffff] PMD -> [ffff880100200000-ffff88016e5fffff] on node 0 [ 0.000000] [ffffea0070000000-ffffea00dfffffff] PMD -> [ffff882000200000-ffff8820701fffff] on node 1 [ 0.000000] [ffffea00e0000000-ffffea014fffffff] PMD -> [ffff884000200000-ffff8840701fffff] on node 2 [ 0.000000] [ffffea0150000000-ffffea01bfffffff] PMD -> [ffff886000200000-ffff8860701fffff] on node 3 [ 0.000000] [ffffea01c0000000-ffffea022fffffff] PMD -> [ffff888000200000-ffff8880701fffff] on node 4 [ 0.000000] [ffffea0230000000-ffffea029fffffff] PMD -> [ffff88a000200000-ffff88a0701fffff] on node 5 [ 0.000000] [ffffea02a0000000-ffffea030fffffff] PMD -> [ffff88c000200000-ffff88c0701fffff] on node 6 [ 0.000000] [ffffea0310000000-ffffea037fffffff] PMD -> [ffff88e000200000-ffff88e0701fffff] on node 7 -v2: change buf to vmemmap_buf instead according to Ingo also add CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER according to Ingo -v3: according to Andrew, use sizeof(name) instead of hard coded 15 Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <1265793639-15071-19-git-send-email-yinghai@kernel.org> Cc: Christoph Lameter <cl@linux-foundation.org> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* sparsemem: Put usemap for one node togetherYinghai Lu2010-02-12
| | | | | | | | | | | Could save some buffer space instead of applying one by one. Could help that system that is going to use early_res instead of bootmem less entries in early_res make search more faster on system with more memory. Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <1265793639-15071-18-git-send-email-yinghai@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* memory hotplug: alloc page from other node in memory onlineShaohua Li2009-09-22
| | | | | | | | | | | | | To initialize hotadded node, some pages are allocated. At that time, the node hasn't memory, this makes the allocation always fail. In such case, let's allocate pages from other nodes. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Yakui Zhao <yakui.zhao@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: mminit_validate_memmodel_limits(): remove redundant testCyrill Gorcunov2009-04-01
| | | | | | | | | | In case if start_pfn overlap the upper bound no need to test end_pfn again since we have it already trimmed. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* meminit section warningsAl Viro2008-11-30
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse.c: removed duplicated includeHuang Weiyi2008-08-12
| | | | | | Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make mm/sparse.c: make a function staticAdrian Bunk2008-07-26
| | | | | | | | | This patch makes the needlessly global sparse_early_mem_map_alloc() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: allocate usemap on the section with pgdatYasunori Goto2008-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Usemaps are allocated on the section which has pgdat by this. Because usemap size is very small, many other sections usemaps are allocated on only one page. If a section has usemap, it can't be removed until removing other sections. This dependency is not desirable for memory removing. Pgdat has similar feature. When a section has pgdat area, it must be the last section for removing on the node. So, if section A has pgdat and section B has usemap for section A, Both sections can't be removed due to dependency each other. To solve this issue, this patch collects usemap on same section with pgdat as much as possible. If other sections doesn't have any dependency, this section will be able to be removed finally. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: David Miller <davem@davemloft.net> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Hiroyuki KAMEZAWA <kamezawa.hiroyu@jp.fujitsu.com> Cc: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: make defensive checks around PFN values registered for memory usageMel Gorman2008-07-24
| | | | | | | | | | | | | | | | | | | | There are a number of different views to how much memory is currently active. There is the arch-independent zone-sizing view, the bootmem allocator and memory models view. Architectures register this information at different times and is not necessarily in sync particularly with respect to some SPARSEMEM limitations. This patch introduces mminit_validate_memmodel_limits() which is able to validate and correct PFN ranges with respect to the memory model. It is only SPARSEMEM that currently validates itself. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "memory hotplug: allocate usemap on the section with pgdat"Andrew Morton2008-04-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This: commit 86f6dae1377523689bd8468fed2f2dd180fc0560 Author: Yasunori Goto <y-goto@jp.fujitsu.com> Date: Mon Apr 28 02:13:33 2008 -0700 memory hotplug: allocate usemap on the section with pgdat Usemaps are allocated on the section which has pgdat by this. Because usemap size is very small, many other sections usemaps are allocated on only one page. If a section has usemap, it can't be removed until removing other sections. This dependency is not desirable for memory removing. Pgdat has similar feature. When a section has pgdat area, it must be the last section for removing on the node. So, if section A has pgdat and section B has usemap for section A, Both sections can't be removed due to dependency each other. To solve this issue, this patch collects usemap on same section with pgdat. If other sections doesn't have any dependency, this section will be able to be removed finally. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> broke davem's sparc64 bootup. Revert it while we work out what went wrong. Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove remaining __FUNCTION__ occurrencesHarvey Harrison2008-04-30
| | | | | | | | __FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: free memmaps allocated by bootmemYasunori Goto2008-04-28
| | | | | | | | | | | | | | | | | | | | | This patch is to free memmaps which is allocated by bootmem. Freeing usemap is not necessary. The pages of usemap may be necessary for other sections. If removing section is last section on the node, its section is the final user of usemap page. (usemaps are allocated on its section by previous patch.) But it shouldn't be freed too, because the section must be logical offline state which all pages are isolated against page allocater. If it is freed, page alloctor may use it which will be removed physically soon. It will be disaster. So, this patch keeps it as it is. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: allocate usemap on the section with pgdatYasunori Goto2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | Usemaps are allocated on the section which has pgdat by this. Because usemap size is very small, many other sections usemaps are allocated on only one page. If a section has usemap, it can't be removed until removing other sections. This dependency is not desirable for memory removing. Pgdat has similar feature. When a section has pgdat area, it must be the last section for removing on the node. So, if section A has pgdat and section B has usemap for section A, Both sections can't be removed due to dependency each other. To solve this issue, this patch collects usemap on same section with pgdat. If other sections doesn't have any dependency, this section will be able to be removed finally. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: align memmap to page sizeYasunori Goto2008-04-28
| | | | | | | | | | | | | To free memmap easier, this patch aligns it to page size. Bootmem allocater may mix some objects in one pages. It's not good for freeing memmap of memory hot-remove. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: register section/node id to freeYasunori Goto2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hotplug memory remove: generic __remove_pages() supportBadari Pulavarty2008-04-28
| | | | | | | | | | | | | | | Generic helper function to remove section mappings and sysfs entries for the section of the memory we are removing. offline_pages() correctly adjusted zone and marked the pages reserved. TODO: Yasunori Goto is working on patches to free up allocations from bootmem. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86_64/mm: check and print vmemmap allocation continuousYinghai Lu2008-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On big systems with lots of memory, don't print out too much during bootup, and make it easy to find if it is continuous. on 256G 8 sockets system will get [ffffe20000000000-ffffe20002bfffff] PMD -> [ffff810001400000-ffff810003ffffff] on node 0 [ffffe2001c700000-ffffe2001c7fffff] potential offnode page_structs [ffffe20002c00000-ffffe2001c7fffff] PMD -> [ffff81000c000000-ffff8100255fffff] on node 0 [ffffe20038700000-ffffe200387fffff] potential offnode page_structs [ffffe2001c800000-ffffe200387fffff] PMD -> [ffff810820200000-ffff81083c1fffff] on node 1 [ffffe20040000000-ffffe2007fffffff] PUD ->ffff811027a00000 on node 2 [ffffe20038800000-ffffe2003fffffff] PMD -> [ffff811020200000-ffff8110279fffff] on node 2 [ffffe20054700000-ffffe200547fffff] potential offnode page_structs [ffffe20040000000-ffffe200547fffff] PMD -> [ffff811027c00000-ffff81103c3fffff] on node 2 [ffffe20070700000-ffffe200707fffff] potential offnode page_structs [ffffe20054800000-ffffe200707fffff] PMD -> [ffff811820200000-ffff81183c1fffff] on node 3 [ffffe20080000000-ffffe200bfffffff] PUD ->ffff81202fa00000 on node 4 [ffffe20070800000-ffffe2007fffffff] PMD -> [ffff812020200000-ffff81202f9fffff] on node 4 [ffffe2008c700000-ffffe2008c7fffff] potential offnode page_structs [ffffe20080000000-ffffe2008c7fffff] PMD -> [ffff81202fc00000-ffff81203c3fffff] on node 4 [ffffe200a8700000-ffffe200a87fffff] potential offnode page_structs [ffffe2008c800000-ffffe200a87fffff] PMD -> [ffff812820200000-ffff81283c1fffff] on node 5 [ffffe200c0000000-ffffe200ffffffff] PUD ->ffff813037a00000 on node 6 [ffffe200a8800000-ffffe200bfffffff] PMD -> [ffff813020200000-ffff8130379fffff] on node 6 [ffffe200c4700000-ffffe200c47fffff] potential offnode page_structs [ffffe200c0000000-ffffe200c47fffff] PMD -> [ffff813037c00000-ffff81303c3fffff] on node 6 [ffffe200c4800000-ffffe200e07fffff] PMD -> [ffff813820200000-ffff81383c1fffff] on node 7 instead of a very long print out... Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* mm: make mem_map allocation continuousYinghai Lu2008-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vmemmap allocation currently has this layout: [ffffe20000000000-ffffe200001fffff] PMD ->ffff810001400000 on node 0 [ffffe20000200000-ffffe200003fffff] PMD ->ffff810001800000 on node 0 [ffffe20000400000-ffffe200005fffff] PMD ->ffff810001c00000 on node 0 [ffffe20000600000-ffffe200007fffff] PMD ->ffff810002000000 on node 0 [ffffe20000800000-ffffe200009fffff] PMD ->ffff810002400000 on node 0 ... note that there is a 2M hole between them - not optimal. the root cause is that usemap (24 bytes) will be allocated after every 2M mem_map, and it will push next vmemmap (2M) to the next (2M) alignment. solution: try to allocate the mem_map continously. after the patch, we get: [ffffe20000000000-ffffe200001fffff] PMD ->ffff810001400000 on node 0 [ffffe20000200000-ffffe200003fffff] PMD ->ffff810001600000 on node 0 [ffffe20000400000-ffffe200005fffff] PMD ->ffff810001800000 on node 0 [ffffe20000600000-ffffe200007fffff] PMD ->ffff810001a00000 on node 0 [ffffe20000800000-ffffe200009fffff] PMD ->ffff810001c00000 on node 0 ... which is the ideal layout. and usemap will share a page because of they are allocated continuously too: sparse_early_usemap_alloc: usemap = ffff810024e00000 size = 24 sparse_early_usemap_alloc: usemap = ffff810024e00080 size = 24 sparse_early_usemap_alloc: usemap = ffff810024e00100 size = 24 sparse_early_usemap_alloc: usemap = ffff810024e00180 size = 24 ... so we make the bootmem allocation more compact and use less memory for usemap => mission accomplished ;-) Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* mm: sparsemem memory_present() fixIngo Molnar2008-04-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix memory corruption and crash on 32-bit x86 systems. If a !PAE x86 kernel is booted on a 32-bit system with more than 4GB of RAM, then we call memory_present() with a start/end that goes outside the scope of MAX_PHYSMEM_BITS. That causes this loop to happily walk over the limit of the sparse memory section map: for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { unsigned long section = pfn_to_section_nr(pfn); struct mem_section *ms; sparse_index_init(section, nid); set_section_nid(section, nid); ms = __nr_to_section(section); if (!ms->section_mem_map) ms->section_mem_map = sparse_encode_early_nid(nid) | SECTION_MARKED_PRESENT; 'ms' will be out of bounds and we'll corrupt a small amount of memory by encoding the node ID and writing SECTION_MARKED_PRESENT (==0x1) over it. The corruption might happen when encoding a non-zero node ID, or due to the SECTION_MARKED_PRESENT which is 0x1: mmzone.h:#define SECTION_MARKED_PRESENT (1UL<<0) The fix is to sanity check anything the architecture passes to sparsemem. This bug seems to be rather old (as old as sparsemem support itself), but the exact incarnation depended on random details like configs, which made this bug more prominent in v2.6.25-to-be. An additional enhancement might be to print a warning about ignored or trimmed memory ranges. Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Christoph Lameter <clameter@sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Nick Piggin <npiggin@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Yinghai Lu <Yinghai.Lu@sun.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix section mismatch warning in sparse.cSam Ravnborg2008-02-05
| | | | | | | | | | | | | | | | Fix following warning: WARNING: mm/built-in.o(.text+0x22069): Section mismatch in reference from the function sparse_early_usemap_alloc() to the function .init.text:__alloc_bootmem_node() static sparse_early_usemap_alloc() were used only by sparse_init() and with sparse_init() annotated _init it is safe to annotate sparse_early_usemap_alloc with __init too. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* is_vmalloc_addr(): Check if an address is within the vmalloc boundariesChristoph Lameter2008-02-05
| | | | | | | | | | | | | | Checking if an address is a vmalloc address is done in a couple of places. Define a common version in mm.h and replace the other checks. Again the include structures suck. The definition of VMALLOC_START and VMALLOC_END is not available in vmalloc.h since highmem.c cannot be included there. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse.c: improve the error handling for sparse_add_one_section()WANG Cong2007-12-17
| | | | | | | | | | | | | | | | Improve the error handling for mm/sparse.c::sparse_add_one_section(). And I see no reason to check 'usemap' until holding the 'pgdat_resize_lock'. [geoffrey.levand@am.sony.com: sparse_index_init() returns -EEXIST] Cc: Christoph Lameter <clameter@sgi.com> Acked-by: Dave Hansen <haveblue@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse.c: check the return value of sparse_index_alloc()WANG Cong2007-12-17
| | | | | | | | | | | Since sparse_index_alloc() can return NULL on memory allocation failure, we must deal with the failure condition when calling it. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "x86_64: allocate sparsemem memmap above 4G"Linus Torvalds2007-10-29
| | | | | | | | | | | | | | | | | | | | | | This reverts commit 2e1c49db4c640b35df13889b86b9d62215ade4b6. First off, testing in Fedora has shown it to cause boot failures, bisected down by Martin Ebourne, and reported by Dave Jobes. So the commit will likely be reverted in the 2.6.23 stable kernels. Secondly, in the 2.6.24 model, x86-64 has now grown support for SPARSEMEM_VMEMMAP, which disables the relevant code anyway, so while the bug is not visible any more, it's become invisible due to the code just being irrelevant and no longer enabled on the only architecture that this ever affected. Reported-by: Dave Jones <davej@redhat.com> Tested-by: Martin Ebourne <fedora@ebourne.me.uk> Cc: Zou Nan hai <nanhai.zou@intel.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: Hot-add with sparsemem-vmemmapYasunori Goto2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | This patch is to avoid panic when memory hot-add is executed with sparsemem-vmemmap. Current vmemmap-sparsemem code doesn't support memory hot-add. Vmemmap must be populated when hot-add. This is for 2.6.23-rc2-mm2. Todo: # Even if this patch is applied, the message "[xxxx-xxxx] potential offnode page_structs" is displayed. To allocate memmap on its node, memmap (and pgdat) must be initialized itself like chicken and egg relationship. # vmemmap_unpopulate will be necessary for followings. - For cancel hot-add due to error. - For unplug. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix corruption of memmap on IA64 SPARSEMEM when mem_section is not a power of 2Mel Gorman2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are problems in the use of SPARSEMEM and pageblock flags that causes problems on ia64. The first part of the problem is that units are incorrect in SECTION_BLOCKFLAGS_BITS computation. This results in a map_section's section_mem_map being treated as part of a bitmap which isn't good. This was evident with an invalid virtual address when mem_init attempted to free bootmem pages while relinquishing control from the bootmem allocator. The second part of the problem occurs because the pageblock flags bitmap is be located with the mem_section. The SECTIONS_PER_ROOT computation using sizeof (mem_section) may not be a power of 2 depending on the size of the bitmap. This renders masks and other such things not power of 2 base. This issue was seen with SPARSEMEM_EXTREME on ia64. This patch moves the bitmap outside of mem_section and uses a pointer instead in the mem_section. The bitmaps are allocated when the section is being initialised. Note that sparse_early_usemap_alloc() does not use alloc_remap() like sparse_early_mem_map_alloc(). The allocation required for the bitmap on x86, the only architecture that uses alloc_remap is typically smaller than a cache line. alloc_remap() pads out allocations to the cache size which would be a needless waste. Credit to Bob Picco for identifying the original problem and effecting a fix for the SECTION_BLOCKFLAGS_BITS calculation. Credit to Andy Whitcroft for devising the best way of allocating the bitmaps only when required for the section. [wli@holomorphy.com: warning fix] Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: William Irwin <bill.irwin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Generic Virtual Memmap support for SPARSEMEMChristoph Lameter2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SPARSEMEM is a pretty nice framework that unifies quite a bit of code over all the arches. It would be great if it could be the default so that we can get rid of various forms of DISCONTIG and other variations on memory maps. So far what has hindered this are the additional lookups that SPARSEMEM introduces for virt_to_page and page_address. This goes so far that the code to do this has to be kept in a separate function and cannot be used inline. This patch introduces a virtual memmap mode for SPARSEMEM, in which the memmap is mapped into a virtually contigious area, only the active sections are physically backed. This allows virt_to_page page_address and cohorts become simple shift/add operations. No page flag fields, no table lookups, nothing involving memory is required. The two key operations pfn_to_page and page_to_page become: #define __pfn_to_page(pfn) (vmemmap + (pfn)) #define __page_to_pfn(page) ((page) - vmemmap) By having a virtual mapping for the memmap we allow simple access without wasting physical memory. As kernel memory is typically already mapped 1:1 this introduces no additional overhead. The virtual mapping must be big enough to allow a struct page to be allocated and mapped for all valid physical pages. This vill make a virtual memmap difficult to use on 32 bit platforms that support 36 address bits. However, if there is enough virtual space available and the arch already maps its 1-1 kernel space using TLBs (f.e. true of IA64 and x86_64) then this technique makes SPARSEMEM lookups even more efficient than CONFIG_FLATMEM. FLATMEM needs to read the contents of the mem_map variable to get the start of the memmap and then add the offset to the required entry. vmemmap is a constant to which we can simply add the offset. This patch has the potential to allow us to make SPARSMEM the default (and even the only) option for most systems. It should be optimal on UP, SMP and NUMA on most platforms. Then we may even be able to remove the other memory models: FLATMEM, DISCONTIG etc. [apw@shadowen.org: config cleanups, resplit code etc] [kamezawa.hiroyu@jp.fujitsu.com: Fix sparsemem_vmemmap init] [apw@shadowen.org: vmemmap: remove excess debugging] [apw@shadowen.org: simplify initialisation code and reduce duplication] [apw@shadowen.org: pull out the vmemmap code into its own file] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparsemem: record when a section has a valid mem_mapAndy Whitcroft2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | We have flags to indicate whether a section actually has a valid mem_map associated with it. This is never set and we rely solely on the present bit to indicate a section is valid. By definition a section is not valid if it has no mem_map and there is a window during init where the present bit is set but there is no mem_map, during which pfn_valid() will return true incorrectly. Use the existing SECTION_HAS_MEM_MAP flag to indicate the presence of a valid mem_map. Switch valid_section{,_nr} and pfn_valid() to this bit. Add a new present_section{,_nr} and pfn_present() interfaces for those users who care to know that a section is going to be valid. [akpm@linux-foundation.org: coding-syle fixes] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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