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* mm/vmalloc.c: eliminate extra loop in pcpu_get_vm_areas error pathKautuk Consul2012-01-12
| | | | | | | | | | | | | | | | | | If either of the vas or vms arrays are not properly kzalloced, then the code jumps to the err_free label. The err_free label runs a loop to check and free each of the array members of the vas and vms arrays which is not required for this situation as none of the array members have been allocated till this point. Eliminate the extra loop we have to go through by introducing a new label err_free2 and then jumping to it. [akpm@linux-foundation.org: remove now-unneeded tests] Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> 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/vmalloc.c: change void* into explict vm_struct*Minchan Kim2012-01-10
| | | | | | | | | | | vmap_area->private is void* but we don't use the field for various purpose but use only for vm_struct. So change it to a vm_struct* with naming to improve for readability and type checking. Signed-off-by: Minchan Kim <minchan@kernel.org> 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>
* Merge branch 'devel-stable' into for-linusRussell King2012-01-05
|\ | | | | | | | | | | Conflicts: arch/arm/kernel/setup.c arch/arm/mach-shmobile/board-kota2.c
| * Merge branch 'vmalloc' of git://git.linaro.org/people/nico/linux into ↵Russell King2011-12-05
| |\ | | | | | | | | | devel-stable
| | * mm: add vm_area_add_early()Nicolas Pitre2011-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing vm_area_register_early() allows for early vmalloc space allocation. However upcoming cleanups in the ARM architecture require that some fixed locations in the vmalloc area be reserved also very early. The name "vm_area_register_early" would have been a good name for the reservation part without the allocation. Since it is already in use with different semantics, let's create vm_area_add_early() instead. Both vm_area_register_early() and vm_area_add_early() can be used together meaning that the former is now implemented using the later where it is ensured that no conflicting areas are added, but no attempt is made to make the allocation scheme in vm_area_register_early() more sophisticated. After all, you must know what you're doing when using those functions. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org
* | | mm/vmalloc.c: remove static declaration of va from __get_vm_area_nodeKautuk Consul2011-12-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Static storage is not required for the struct vmap_area in __get_vm_area_node. Removing "static" to store this variable on the stack instead. Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> 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: vmalloc: check for page allocation failure before vmlist insertionMel Gorman2011-12-09
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f5252e00 ("mm: avoid null pointer access in vm_struct via /proc/vmallocinfo") adds newly allocated vm_structs to the vmlist after it is fully initialised. Unfortunately, it did not check that __vmalloc_area_node() successfully populated the area. In the event of allocation failure, the vmalloc area is freed but the pointer to freed memory is inserted into the vmlist leading to a a crash later in get_vmalloc_info(). This patch adds a check for ____vmalloc_area_node() failure within __vmalloc_node_range. It does not use "goto fail" as in the previous error path as a warning was already displayed by __vmalloc_area_node() before it called vfree in its failure path. Credit goes to Luciano Chavez for doing all the real work of identifying exactly where the problem was. Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com> Tested-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [3.1.x+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / xen: map foreign pages for shared rings by updating the PTEs directlyDavid Vrabel2011-11-16
|/ | | | | | | | | | | | | | | | When mapping a foreign page with xenbus_map_ring_valloc() with the GNTTABOP_map_grant_ref hypercall, set the GNTMAP_contains_pte flag and pass a pointer to the PTE (in init_mm). After the page is mapped, the usual fault mechanism can be used to update additional MMs. This allows the vmalloc_sync_all() to be removed from alloc_vm_area(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> [v1: Squashed fix by Michal for no-mmu case] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
* mm/vmalloc.c: report more vmalloc failuresJoe Perches2011-10-31
| | | | | | | | | | | | | | Some vmalloc failure paths do not report OOM conditions. Add warn_alloc_failed, which also does a dump_stack, to those failure paths. This allows more site specific vmalloc failure logging message printks to be removed. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: neaten warn_alloc_failedJoe Perches2011-10-31
| | | | | | | | | | | | Add __attribute__((format (printf...) to the function to validate format and arguments. Use vsprintf extension %pV to avoid any possible message interleaving. Coalesce format string. Convert printks/pr_warning to pr_warn. [akpm@linux-foundation.org: use the __printf() macro] Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: avoid null pointer access in vm_struct via /proc/vmallocinfoMitsuo Hayasaka2011-10-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The /proc/vmallocinfo shows information about vmalloc allocations in vmlist that is a linklist of vm_struct. It, however, may access pages field of vm_struct where a page was not allocated. This results in a null pointer access and leads to a kernel panic. Why this happens: In __vmalloc_node_range() called from vmalloc(), newly allocated vm_struct is added to vmlist at __get_vm_area_node() and then, some fields of vm_struct such as nr_pages and pages are set at __vmalloc_area_node(). In other words, it is added to vmlist before it is fully initialized. At the same time, when the /proc/vmallocinfo is read, it accesses the pages field of vm_struct according to the nr_pages field at show_numa_info(). Thus, a null pointer access happens. The patch adds the newly allocated vm_struct to the vmlist *after* it is fully initialized. So, it can avoid accessing the pages field with unallocated page when show_numa_info() is called. Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: sync vmalloc address space page tables in alloc_vm_area()David Vrabel2011-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xen backend drivers (e.g., blkback and netback) would sometimes fail to map grant pages into the vmalloc address space allocated with alloc_vm_area(). The GNTTABOP_map_grant_ref would fail because Xen could not find the page (in the L2 table) containing the PTEs it needed to update. (XEN) mm.c:3846:d0 Could not find L1 PTE for address fbb42000 netback and blkback were making the hypercall from a kernel thread where task->active_mm != &init_mm and alloc_vm_area() was only updating the page tables for init_mm. The usual method of deferring the update to the page tables of other processes (i.e., after taking a fault) doesn't work as a fault cannot occur during the hypercall. This would work on some systems depending on what else was using vmalloc. Fix this by reverting ef691947d8a3 ("vmalloc: remove vmalloc_sync_all() from alloc_vm_area()") and add a comment to explain why it's needed. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Keir Fraser <keir.xen@gmail.com> Cc: <stable@kernel.org> [3.0.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix wrong vmap address calculations with odd NR_CPUS valuesClemens Ladisch2011-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit db64fe02258f ("mm: rewrite vmap layer") introduced code that does address calculations under the assumption that VMAP_BLOCK_SIZE is a power of two. However, this might not be true if CONFIG_NR_CPUS is not set to a power of two. Wrong vmap_block index/offset values could lead to memory corruption. However, this has never been observed in practice (or never been diagnosed correctly); what caught this was the BUG_ON in vb_alloc() that checks for inconsistent vmap_block indices. To fix this, ensure that VMAP_BLOCK_SIZE always is a power of two. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=31572 Reported-by: Pavel Kysilka <goldenfish@linuxsoft.cz> Reported-by: Matias A. Fonzo <selk@dragora.org> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Nick Piggin <npiggin@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: 2.6.28+ <stable@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic: use <linux/atomic.h>Arun Sharma2011-07-26
| | | | | | | | | | | | | | This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc,rcu: Convert call_rcu(rcu_free_vb) to kfree_rcu()Lai Jiangshan2011-07-20
| | | | | | | | | | | | The rcu callback rcu_free_vb() just calls a kfree(), so we use kfree_rcu() instead of the call_rcu(rcu_free_vb). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Namhyung Kim <namhyung@gmail.com> Cc: David Rientjes <rientjes@google.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* vmalloc,rcu: Convert call_rcu(rcu_free_va) to kfree_rcu()Lai Jiangshan2011-07-20
| | | | | | | | | | | | The rcu callback rcu_free_va() just calls a kfree(), so we use kfree_rcu() instead of the call_rcu(rcu_free_va). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Namhyung Kim <namhyung@gmail.com> Cc: David Rientjes <rientjes@google.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* Merge branch 'upstream/tidy-xen-mmu-2.6.39' of ↵Linus Torvalds2011-05-26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen * 'upstream/tidy-xen-mmu-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: xen: fix compile without CONFIG_XEN_DEBUG_FS Use arbitrary_virt_to_machine() to deal with ioremapped pud updates. Use arbitrary_virt_to_machine() to deal with ioremapped pmd updates. xen/mmu: remove all ad-hoc stats stuff xen: use normal virt_to_machine for ptes xen: make a pile of mmu pvop functions static vmalloc: remove vmalloc_sync_all() from alloc_vm_area() xen: condense everything onto xen_set_pte xen: use mmu_update for xen_set_pte_at() xen: drop all the special iomap pte paths.
| * vmalloc: remove vmalloc_sync_all() from alloc_vm_area()Jeremy Fitzhardinge2011-05-20
| | | | | | | | | | | | | | There's no need for it: it will get faulted into the current pagetable as needed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | mm: print vmalloc() state after allocation failuresDave Hansen2011-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I was tracking down a page allocation failure that ended up in vmalloc(). Since vmalloc() uses 0-order pages, if somebody asks for an insane amount of memory, we'll still get a warning with "order:0" in it. That's not very useful. During recovery, vmalloc() also nicely frees all of the memory that it got up to the point of the failure. That is wonderful, but it also quickly hides any issues. We have a much different sitation if vmalloc() repeatedly fails 10GB in to: vmalloc(100 * 1<<30); versus repeatedly failing 4096 bytes in to a: vmalloc(8192); This patch will print out messages that look like this: [ 68.123503] vmalloc: allocation failure, allocated 6680576 of 13426688 bytes [ 68.124218] bash: page allocation failure: order:0, mode:0xd2 [ 68.124811] Pid: 3770, comm: bash Not tainted 2.6.39-rc3-00082-g85f2e68-dirty #333 [ 68.125579] Call Trace: [ 68.125853] [<ffffffff810f6da6>] warn_alloc_failed+0x146/0x170 [ 68.126464] [<ffffffff8107e05c>] ? printk+0x6c/0x70 [ 68.126791] [<ffffffff8112b5d4>] ? alloc_pages_current+0x94/0xe0 [ 68.127661] [<ffffffff8111ed37>] __vmalloc_node_range+0x237/0x290 ... The 'order' variable is added for clarity when calling warn_alloc_failed() to avoid having an unexplained '0' as an argument. The 'tmp_mask' is because adding an open-coded '| __GFP_NOWARN' would take us over 80 columns for the alloc_pages_node() call. If we are going to add a line, it might as well be one that makes the sucker easier to read. As a side issue, I also noticed that ctl_ioctl() does vmalloc() based solely on an unverified value passed in from userspace. Granted, it's under CAP_SYS_ADMIN, but it still frightens me a bit. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/vmalloc: remove guard page from between vmap blocksJohannes Weiner2011-05-25
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vmap allocator is used to, among other things, allocate per-cpu vmap blocks, where each vmap block is naturally aligned to its own size. Obviously, leaving a guard page after each vmap area forbids packing vmap blocks efficiently and can make the kernel run out of possible vmap blocks long before overall vmap space is exhausted. The new interface to map a user-supplied page array into linear vmalloc space (vm_map_ram) insists on allocating from a vmap block (instead of falling back to a custom area) when the area size is below a certain threshold. With heavy users of this interface (e.g. XFS) and limited vmalloc space on 32-bit, vmap block exhaustion is a real problem. Remove the guard page from the core vmap allocator. vmalloc and the old vmap interface enforce a guard page on their own at a higher level. Note that without this patch, we had accidental guard pages after those vm_map_ram areas that happened to be at the end of a vmap block, but not between every area. This patch removes this accidental guard page only. If we want guard pages after every vm_map_ram area, this should be done separately. And just like with vmalloc and the old interface on a different level, not in the core allocator. Mel pointed out: "If necessary, the guard page could be reintroduced as a debugging-only option (CONFIG_DEBUG_PAGEALLOC?). Otherwise it seems reasonable." Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Dave Chinner <david@fromorbit.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc: remove confusing comment on vwrite()Namhyung Kim2011-03-22
| | | | | | | | | | | KM_USER1 is never used for vwrite() path so the caller doesn't need to guarantee it is not used. Only the caller should guarantee is KM_USER0 and it is commented already. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-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>
* mm: vmap area cacheNick Piggin2011-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a free area cache for the vmalloc virtual address allocator, based on the algorithm used by the user virtual memory allocator. This reduces the number of rbtree operations and linear traversals over the vmap extents in order to find a free area, by starting off at the last point that a free area was found. The free area cache is reset if areas are freed behind it, or if we are searching for a smaller area or alignment than last time. So allocation patterns are not changed (verified by corner-case and random test cases in userspace testing). This solves a regression caused by lazy vunmap TLB purging introduced in db64fe02 (mm: rewrite vmap layer). That patch will leave extents in the vmap allocator after they are vunmapped, and until a significant number accumulate that can be flushed in a single batch. So in a workload that vmalloc/vfree frequently, a chain of extents will build up from VMALLOC_START address, which have to be iterated over each time (giving an O(n) type of behaviour). After this patch, the search will start from where it left off, giving closer to an amortized O(1). This is verified to solve regressions reported Steven in GFS2, and Avi in KVM. Hugh's update: : I tried out the recent mmotm, and on one machine was fortunate to hit : the BUG_ON(first->va_start < addr) which seems to have been stalling : your vmap area cache patch ever since May. : I can get you addresses etc, I did dump a few out; but once I stared : at them, it was easier just to look at the code: and I cannot see how : you would be so sure that first->va_start < addr, once you've done : that addr = ALIGN(max(...), align) above, if align is over 0x1000 : (align was 0x8000 or 0x4000 in the cases I hit: ioremaps like Steve). : I originally got around it by just changing the : if (first->va_start < addr) { : to : while (first->va_start < addr) { : without thinking about it any further; but that seemed unsatisfactory, : why would we want to loop here when we've got another very similar : loop just below it? : I am never going to admit how long I've spent trying to grasp your : "while (n)" rbtree loop just above this, the one with the peculiar : if (!first && tmp->va_start < addr + size) : in. That's unfamiliar to me, I'm guessing it's designed to save a : subsequent rb_next() in a few circumstances (at risk of then setting : a wrong cached_hole_size?); but they did appear few to me, and I didn't : feel I could sign off something with that in when I don't grasp it, : and it seems responsible for extra code and mistaken BUG_ON below it. : I've reverted to the familiar rbtree loop that find_vma() does (but : with va_end >= addr as you had, to respect the additional guard page): : and then (given that cached_hole_size starts out 0) I don't see the : need for any complications below it. If you do want to keep that loop : as you had it, please add a comment to explain what it's trying to do, : and where addr is relative to first when you emerge from it. : Aren't your tests "size <= cached_hole_size" and : "addr + size > first->va_start" forgetting the guard page we want : before the next area? I've changed those. : I have not changed your many "addr + size - 1 < addr" overflow tests, : but have since come to wonder, shouldn't they be "addr + size < addr" : tests - won't the vend checks go wrong if addr + size is 0? : I have added a few comments - Wolfgang Wander's 2.6.13 description of : 1363c3cd8603a913a27e2995dccbd70d5312d8e6 Avoiding mmap fragmentation : helped me a lot, perhaps a pointer to that would be good too. And I found : it easier to understand when I renamed cached_start slightly and moved the : overflow label down. : This patch would go after your mm-vmap-area-cache.patch in mmotm. : Trivially, nobody is going to get that BUG_ON with this patch, and it : appears to work fine on my machines; but I have not given it anything like : the testing you did on your original, and may have broken all the : performance you were aiming for. Please take a look and test it out : integrate with yours if you're satisfied - thanks. [akpm@linux-foundation.org: add locking comment] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reported-and-tested-by: Steven Whitehouse <swhiteho@redhat.com> Reported-and-tested-by: Avi Kivity <avi@redhat.com> Tested-by: "Barry J. Marson" <bmarson@redhat.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'release' of ↵Linus Torvalds2011-01-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (59 commits) ACPI / PM: Fix build problems for !CONFIG_ACPI related to NVS rework ACPI: fix resource check message ACPI / Battery: Update information on info notification and resume ACPI: Drop device flag wake_capable ACPI: Always check if _PRW is present before trying to evaluate it ACPI / PM: Check status of power resources under mutexes ACPI / PM: Rename acpi_power_off_device() ACPI / PM: Drop acpi_power_nocheck ACPI / PM: Drop acpi_bus_get_power() Platform / x86: Make fujitsu_laptop use acpi_bus_update_power() ACPI / Fan: Rework the handling of power resources ACPI / PM: Register power resource devices as soon as they are needed ACPI / PM: Register acpi_power_driver early ACPI / PM: Add function for updating device power state consistently ACPI / PM: Add function for device power state initialization ACPI / PM: Introduce __acpi_bus_get_power() ACPI / PM: Introduce function for refcounting device power resources ACPI / PM: Add functions for manipulating lists of power resources ACPI / PM: Prevent acpi_power_get_inferred_state() from making changes ACPICA: Update version to 20101209 ...
| * ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type supportHuang Ying2011-01-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generic Hardware Error Source provides a way to report platform hardware errors (such as that from chipset). It works in so called "Firmware First" mode, that is, hardware errors are reported to firmware firstly, then reported to Linux by firmware. This way, some non-standard hardware error registers or non-standard hardware link can be checked by firmware to produce more valuable hardware error information for Linux. This patch adds POLL/IRQ/NMI notification types support. Because the memory area used to transfer hardware error information from BIOS to Linux can be determined only in NMI, IRQ or timer handler, but general ioremap can not be used in atomic context, so a special version of atomic ioremap is implemented for that. Known issue: - Error information can not be printed for recoverable errors notified via NMI, because printk is not NMI-safe. Will fix this via delay printing to IRQ context via irq_work or make printk NMI-safe. v2: - adjust printk format per comments. Signed-off-by: Huang Ying <ying.huang@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
* | vmalloc: remove redundant unlikely()Tobias Klauser2011-01-13
| | | | | | | | | | | | | | | | | | IS_ERR() already implies unlikely(), so it can be omitted here. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: unify module_alloc code for vmallocDavid Rientjes2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Four architectures (arm, mips, sparc, x86) use __vmalloc_area() for module_init(). Much of the code is duplicated and can be generalized in a globally accessible function, __vmalloc_node_range(). __vmalloc_node() now calls into __vmalloc_node_range() with a range of [VMALLOC_START, VMALLOC_END) for functionally equivalent behavior. Each architecture may then use __vmalloc_node_range() directly to remove the duplication of code. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: remove gfp mask from pcpu_get_vm_areasDavid Rientjes2011-01-13
| | | | | | | | | | | | | | | | | | | | | | pcpu_get_vm_areas() only uses GFP_KERNEL allocations, so remove the gfp_t formal and use the mask internally. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: remove unused get_vm_area_nodeDavid Rientjes2011-01-13
| | | | | | | | | | | | | | | | | | get_vm_area_node() is unused in the kernel and can thus be removed. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: convert sprintf_symbol to %pSJoe Perches2011-01-13
|/ | | | | | | | Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc: eagerly clear ptes on vunmapJeremy Fitzhardinge2010-12-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On stock 2.6.37-rc4, running: # mount lilith:/export /mnt/lilith # find /mnt/lilith/ -type f -print0 | xargs -0 file crashes the machine fairly quickly under Xen. Often it results in oops messages, but the couple of times I tried just now, it just hung quietly and made Xen print some rude messages: (XEN) mm.c:2389:d80 Bad type (saw 7400000000000001 != exp 3000000000000000) for mfn 1d7058 (pfn 18fa7) (XEN) mm.c:964:d80 Attempt to create linear p.t. with write perms (XEN) mm.c:2389:d80 Bad type (saw 7400000000000010 != exp 1000000000000000) for mfn 1d2e04 (pfn 1d1fb) (XEN) mm.c:2965:d80 Error while pinning mfn 1d2e04 Which means the domain tried to map a pagetable page RW, which would allow it to map arbitrary memory, so Xen stopped it. This is because vm_unmap_ram() left some pages mapped in the vmalloc area after NFS had finished with them, and those pages got recycled as pagetable pages while still having these RW aliases. Removing those mappings immediately removes the Xen-visible aliases, and so it has no problem with those pages being reused as pagetable pages. Deferring the TLB flush doesn't upset Xen because it can flush the TLB itself as needed to maintain its invariants. When unmapping a region in the vmalloc space, clear the ptes immediately. There's no point in deferring this because there's no amortization benefit. The TLBs are left dirty, and they are flushed lazily to amortize the cost of the IPIs. This specific motivation for this patch is an oops-causing regression since 2.6.36 when using NFS under Xen, triggered by the NFS client's use of vm_map_ram() introduced in 56e4ebf877b60 ("NFS: readdir with vmapped pages") . XFS also uses vm_map_ram() and could cause similar problems. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Bryan Schumaker <bjschuma@netapp.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Alex Elder <aelder@sgi.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add vzalloc() and vzalloc_node() helpersDave Young2010-10-26
| | | | | | | | | | | | | | Add vzalloc() and vzalloc_node() to encapsulate the vmalloc-then-memset-zero operation. Use __GFP_ZERO to zero fill the allocated memory. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Acked-by: Greg Ungerer <gerg@snapgear.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc: annotate lock context change on s_start/stop()Namhyung Kim2010-10-26
| | | | | | | | | s_start() and s_stop() grab/release vmlist_lock but were missing proper annotations. Add them. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc: rename temporary variable in __insert_vmap_area()Namhyung Kim2010-10-26
| | | | | | | | | | | Rename redundant 'tmp' to fix following sparse warnings: mm/vmalloc.c:296:34: warning: symbol 'tmp' shadows an earlier one mm/vmalloc.c:293:24: originally declared here Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2010-10-22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: update comments to reflect that percpu allocations are always zero-filled percpu: Optimize __get_cpu_var() x86, percpu: Optimize this_cpu_ptr percpu: clear memory allocated with the km allocator percpu: fix build breakage on s390 and cleanup build configuration tests percpu: use percpu allocator on UP too percpu: reduce PCPU_MIN_UNIT_SIZE to 32k vmalloc: pcpu_get/free_vm_areas() aren't needed on UP Fixed up trivial conflicts in include/linux/percpu.h
| * vmalloc: pcpu_get/free_vm_areas() aren't needed on UPTejun Heo2010-09-08
| | | | | | | | | | | | | | | | | | These functions are used only by percpu memory allocator on SMP. Don't build them on UP. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Nick Piggin <npiggin@kernel.dk> Reviewed-by: Chrsitoph Lameter <cl@linux.com>
* | mm, x86: Saving vmcore with non-lazy freeing of vmasCliff Wickman2010-09-17
|/ | | | | | | | | | | | | | | | | | | | | During the reading of /proc/vmcore the kernel is doing ioremap()/iounmap() repeatedly. And the buildup of un-flushed vm_area_struct's is causing a great deal of overhead. (rb_next() is chewing up most of that time). This solution is to provide function set_iounmap_nonlazy(). It causes a subsequent call to iounmap() to immediately purge the vma area (with try_purge_vmap_area_lazy()). With this patch we have seen the time for writing a 250MB compressed dump drop from 71 seconds to 44 seconds. Signed-off-by: Cliff Wickman <cpw@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: kexec@lists.infradead.org Cc: <stable@kernel.org> LKML-Reference: <E1OwHZ4-0005WK-Tw@eag09.americas.sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'stable/xen-swiotlb-0.8.6' of ↵Linus Torvalds2010-08-12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/xen-swiotlb-0.8.6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: x86: Detect whether we should use Xen SWIOTLB. pci-swiotlb-xen: Add glue code to setup dma_ops utilizing xen_swiotlb_* functions. swiotlb-xen: SWIOTLB library for Xen PV guest with PCI passthrough. xen/mmu: inhibit vmap aliases rather than trying to clear them out vmap: add flag to allow lazy unmap to be disabled at runtime xen: Add xen_create_contiguous_region xen: Rename the balloon lock xen: Allow unprivileged Xen domains to create iomap pages xen: use _PAGE_IOMAP in ioremap to do machine mappings Fix up trivial conflicts (adding both xen swiotlb and xen pci platform driver setup close to each other) in drivers/xen/{Kconfig,Makefile} and include/xen/xen-ops.h
| * vmap: add flag to allow lazy unmap to be disabled at runtimeJeremy Fitzhardinge2010-07-27
| | | | | | | | | | | | | | | | | | Add a flag to force lazy_max_pages() to zero to prevent any outstanding mapped pages. We'll need this for Xen. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Nick Piggin <npiggin@suse.de>
* | mm/vmalloc.c: check kmalloc() return valueKulikov Vasiliy2010-08-09
| | | | | | | | | | | | | | | | | | kmalloc() may fail, if so return -ENOMEM. Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: use ERR_CASTJulia Lawall2010-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)). The former makes more clear what is the purpose of the operation, which otherwise looks like a no-op. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ type T; T x; identifier f; @@ T f (...) { <+... - ERR_PTR(PTR_ERR(x)) + x ...+> } @@ expression x; @@ - ERR_PTR(PTR_ERR(x)) + ERR_CAST(x) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> 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>
* | x86, ioremap: Fix incorrect physical address handling in PAE modeKenji Kaneshige2010-07-09
|/ | | | | | | | | | | | | | | | | | Current x86 ioremap() doesn't handle physical address higher than 32-bit properly in X86_32 PAE mode. When physical address higher than 32-bit is passed to ioremap(), higher 32-bits in physical address is cleared wrongly. Due to this bug, ioremap() can map wrong address to linear address space. In my case, 64-bit MMIO region was assigned to a PCI device (ioat device) on my system. Because of the ioremap()'s bug, wrong physical address (instead of MMIO region) was mapped to linear address space. Because of this, loading ioatdma driver caused unexpected behavior (kernel panic, kernel hangup, ...). Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> LKML-Reference: <4C1AE680.7090408@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* mm: purge fragmented percpu vmap blocksNick Piggin2010-02-02
| | | | | | | | | | | | | | | | | | | | | | | Improve handling of fragmented per-CPU vmaps. We previously don't free up per-CPU maps until all its addresses have been used and freed. So fragmented blocks could fill up vmalloc space even if they actually had no active vmap regions within them. Add some logic to allow all CPUs to have these blocks purged in the case of failure to allocate a new vm area, and also put some logic to trim such blocks of a current CPU if we hit them in the allocation path (so as to avoid a large build up of them). Christoph reported some vmap allocation failures when using the per CPU vmap APIs in XFS, which cannot be reproduced after this patch and the previous bug fix. Cc: linux-mm@kvack.org Cc: stable@kernel.org Tested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Nick Piggin <npiggin@suse.de> -- Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: percpu-vmap fix RCU list walkingNick Piggin2010-02-02
| | | | | | | | | | | | | | | | | | | | | | | RCU list walking of the per-cpu vmap cache was broken. It did not use RCU primitives, and also the union of free_list and rcu_head is obviously wrong (because free_list is indeed the list we are RCU walking). While we are there, remove a couple of unused fields from an earlier iteration. These APIs aren't actually used anywhere, because of problems with the XFS conversion. Christoph has now verified that the problems are solved with these patches. Also it is an exported interface, so I think it will be good to be merged now (and Christoph wants to get the XFS changes into their local tree). Cc: stable@kernel.org Cc: linux-mm@kvack.org Tested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Nick Piggin <npiggin@suse.de> -- Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc: remove BUG_ON due to racy counting of VM_LAZY_FREEYongseok Koh2010-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In free_unmap_area_noflush(), va->flags is marked as VM_LAZY_FREE first, and then vmap_lazy_nr is increased atomically. But, in __purge_vmap_area_lazy(), while traversing of vmap_are_list, nr is counted by checking VM_LAZY_FREE is set to va->flags. After counting the variable nr, kernel reads vmap_lazy_nr atomically and checks a BUG_ON condition whether nr is greater than vmap_lazy_nr to prevent vmap_lazy_nr from being negative. The problem is that, if interrupted right after marking VM_LAZY_FREE, increment of vmap_lazy_nr can be delayed. Consequently, BUG_ON condition can be met because nr is counted more than vmap_lazy_nr. It is highly probable when vmalloc/vfree are called frequently. This scenario have been verified by adding delay between marking VM_LAZY_FREE and increasing vmap_lazy_nr in free_unmap_area_noflush(). Even the vmap_lazy_nr is for checking high watermark, it never be the strict watermark. Although the BUG_ON condition is to prevent vmap_lazy_nr from being negative, vmap_lazy_nr is signed variable. So, it could go down to negative value temporarily. Consequently, removing the BUG_ON condition is proper. A possible BUG_ON message is like the below. kernel BUG at mm/vmalloc.c:517! invalid opcode: 0000 [#1] SMP EIP: 0060:[<c04824a4>] EFLAGS: 00010297 CPU: 3 EIP is at __purge_vmap_area_lazy+0x144/0x150 EAX: ee8a8818 EBX: c08e77d4 ECX: e7c7ae40 EDX: c08e77ec ESI: 000081fe EDI: e7c7ae60 EBP: e7c7ae64 ESP: e7c7ae3c DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Call Trace: [<c0482ad9>] free_unmap_vmap_area_noflush+0x69/0x70 [<c0482b02>] remove_vm_area+0x22/0x70 [<c0482c15>] __vunmap+0x45/0xe0 [<c04831ec>] vmalloc+0x2c/0x30 Code: 8d 59 e0 eb 04 66 90 89 cb 89 d0 e8 87 fe ff ff 8b 43 20 89 da 8d 48 e0 8d 43 20 3b 04 24 75 e7 fe 05 a8 a5 a3 c0 e9 78 ff ff ff <0f> 0b eb fe 90 8d b4 26 00 00 00 00 56 89 c6 b8 ac a5 a3 c0 31 EIP: [<c04824a4>] __purge_vmap_area_lazy+0x144/0x150 SS:ESP 0068:e7c7ae3c [ See also http://marc.info/?l=linux-kernel&m=126335856228090&w=2 ] Signed-off-by: Yongseok Koh <yongseok.koh@samsung.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmalloc(): adjust gfp mask passed on nested vmalloc() invocationJan Beulich2009-12-15
| | | | | | | | | | | | | - avoid wasting more precious resources (DMA or DMA32 pools), when being called through vmalloc_32{,_user}() - explicitly allow using high memory here even if the outer allocation request doesn't allow it Signed-off-by: Jan Beulich <jbeulich@novell.com> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-12-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits) m68k: rename global variable vmalloc_end to m68k_vmalloc_end percpu: add missing per_cpu_ptr_to_phys() definition for UP percpu: Fix kdump failure if booted with percpu_alloc=page percpu: make misc percpu symbols unique percpu: make percpu symbols in ia64 unique percpu: make percpu symbols in powerpc unique percpu: make percpu symbols in x86 unique percpu: make percpu symbols in xen unique percpu: make percpu symbols in cpufreq unique percpu: make percpu symbols in oprofile unique percpu: make percpu symbols in tracer unique percpu: make percpu symbols under kernel/ and mm/ unique percpu: remove some sparse warnings percpu: make alloc_percpu() handle array types vmalloc: fix use of non-existent percpu variable in put_cpu_var() this_cpu: Use this_cpu_xx in trace_functions_graph.c this_cpu: Use this_cpu_xx for ftrace this_cpu: Use this_cpu_xx in nmi handling this_cpu: Use this_cpu operations in RCU this_cpu: Use this_cpu ops for VM statistics ... Fix up trivial (famous last words) global per-cpu naming conflicts in arch/x86/kvm/svm.c mm/slab.c
| * vmalloc: fix use of non-existent percpu variable in put_cpu_var()Tejun Heo2009-10-29
| | | | | | | | | | | | | | | | | | vmalloc used non-existent percpu variable vmap_cpu_blocks instead of the intended vmap_block_queue. This went unnoticed because put_cpu_var() didn't evaluate the parameter. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Nick Piggin <npiggin@suse.de>
* | headers: remove sched.h from interrupt.hAlexey Dobriyan2009-10-11
| | | | | | | | | | | | | | | | After m68k's task_thread_info() doesn't refer to current, it's possible to remove sched.h from interrupt.h and not break m68k! Many thanks to Heiko Carstens for allowing this. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* | Merge branch 'sparc-perf-events-fixes-for-linus' of ↵Linus Torvalds2009-10-08
|\ \ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sparc-perf-events-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mm, perf_event: Make vmalloc_user() align base kernel virtual address to SHMLBA perf_event: Provide vmalloc() based mmap() backing
| * | mm, perf_event: Make vmalloc_user() align base kernel virtual address to SHMLBADavid Miller2009-10-08
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a vmalloc'd area is mmap'd into userspace, some kind of co-ordination is necessary for this to work on platforms with cpu D-caches which can have aliases. Otherwise kernel side writes won't be seen properly in userspace and vice versa. If the kernel side mapping and the user side one have the same alignment, modulo SHMLBA, this can work as long as VM_SHARED is shared of VMA and for all current users this is true. VM_SHARED will force SHMLBA alignment of the user side mmap on platforms with D-cache aliasing matters. The bulk of this patch is just making it so that a specific alignment can be passed down into __get_vm_area_node(). All existing callers pass in '1' which preserves existing behavior. vmalloc_user() gives SHMLBA for the alignment. As a side effect this should get the video media drivers and other vmalloc_user() users into more working shape on such systems. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <200909211922.n8LJMYjw029425@imap1.linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>