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* Fix nasty ncpfs symlink handling bug.Linus Torvalds2005-08-19
| | | | | | | | | | | | | | | | | | This bug could cause oopses and page state corruption, because ncpfs used the generic page-cache symlink handlign functions. But those functions only work if the page cache is guaranteed to be "stable", ie a page that was installed when the symlink walk was started has to still be installed in the page cache at the end of the walk. We could have fixed ncpfs to not use the generic helper routines, but it is in many ways much cleaner to instead improve on the symlink walking helper routines so that they don't require that absolute stability. We do this by allowing "follow_link()" to return a error-pointer as a cookie, which is fed back to the cleanup "put_link()" routine. This also simplifies NFS symlink handling. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix hugepage crash on failing mmap()David Gibson2005-08-05
| | | | | | | | | | | | | | | | This patch fixes a crash in the hugepage code. unmap_hugepage_area() was assuming that (due to prefault) PTEs must exist for all the area in question. However, this may not be the case, if mmap() encounters an error before the prefault and calls unmap_region() to clean up any partial mapping. Depending on the hugepage configuration, this crash can be triggered by an unpriveleged user. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] __vm_enough_memory() signedness fixSimon Derr2005-08-05
| | | | | | | | | | | | | | | | | | | | | | | | | We have found what seems to be a small bug in __vm_enough_memory() when sysctl_overcommit_memory is set to OVERCOMMIT_NEVER. When this bug occurs the systems fails to boot, with /sbin/init whining about fork() returning ENOMEM. We hunted down the problem to this: The deferred update mecanism used in vm_acct_memory(), on a SMP system, allows the vm_committed_space counter to have a negative value. This should not be a problem since this counter is known to be inaccurate. But in __vm_enough_memory() this counter is compared to the `allowed' variable, which is an unsigned long. This comparison is broken since it will consider the negative values of vm_committed_space to be huge positive values, resulting in a memory allocation failure. Signed-off-by: <Jean-Marc.Saffroy@ext.bull.net> Signed-off-by: <Simon.Derr@bull.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix VmSize and VmData after mremapHugh Dickins2005-08-04
| | | | | | | | | | | | | | mremap's move_vma is applying __vm_stat_account to the old vma which may have already been freed: move it to just before the do_munmap. mremapping to and fro with CONFIG_DEBUG_SLAB=y showed /proc/<pid>/status VmSize and VmData wrapping just like in kernel bugzilla #4842, and fixed by this patch - worth including in 2.6.13, though not yet confirmed that it fixes that specific report from Frank van Maarseveen. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Fix up recent get_user_pages() handlingLinus Torvalds2005-08-03
| | | | | | | The VM_FAULT_WRITE thing is an extra bit, not a valid return value, and has to be treated as such by get_user_pages(). Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix get_user_pages bugNick Piggin2005-08-03
| | | | | | | | | | | | | | | | | | | | | | | Checking pte_dirty instead of pte_write in __follow_page is problematic for s390, and for copy_one_pte which leaves dirty when clearing write. So revert __follow_page to check pte_write as before, and make do_wp_page pass back a special extra VM_FAULT_WRITE bit to say it has done its full job: once get_user_pages receives this value, it no longer requires pte_write in __follow_page. But most callers of handle_mm_fault, in the various architectures, have switch statements which do not expect this new case. To avoid changing them all in a hurry, make an inline wrapper function (using the old name) that masks off the new bit, and use the extended interface with double underscores. Yes, we do have a call to do_wp_page from do_swap_page, but no need to change that: in rare case it's needed, another do_wp_page will follow. Signed-off-by: Hugh Dickins <hugh@veritas.com> [ Cleanups by Nick Piggin ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sys_set_mempolicy() doesnt check if mode < 0Eric Dumazet2005-08-02
| | | | | | | | | | | | A kernel BUG() is triggered by a call to set_mempolicy() with a negative first argument. This is because the mode is declared as an int, and the validity check doesnt check < 0 values. Alternatively, mode could be declared as unsigned int or unsigned long. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: access of some bad addressHugh Dickins2005-08-02
| | | | | | | | | | | | | | x86_64 has a large sparse gate area between VSYSCALL_START and VSYSCALL_END, not all of it presently backed by pmds. Alexander Nyberg has found that in some circumstances gdb may try to ptrace here, and hit get_user_pages BUG_ON. It seems odd that gdb should be accessing here, but it certainly shouldn't crash in this way: relax BUG_ON to -EFAULT. Fixes kernel bugzilla #4801. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Fix get_user_pages() race for write accessLinus Torvalds2005-08-01
| | | | | | | | | | | | | | | | | | There's no real guarantee that handle_mm_fault() will always be able to break a COW situation - if an update from another thread ends up modifying the page table some way, handle_mm_fault() may end up requiring us to re-try the operation. That's normally fine, but get_user_pages() ended up re-trying it as a read, and thus a write access could in theory end up losing the dirty bit or be done on a page that had not been properly COW'ed. This makes get_user_pages() always retry write accesses as write accesses by making "follow_page()" require that a writable follow has the dirty bit set. That simplifies the code and solves the race: if the COW break fails for some reason, we'll just loop around and try again. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix NUMA node sizing in nr_free_zone_pagesMartin J. Bligh2005-07-30
| | | | | | | | | | | | | | | | | We are iterating over all nodes in nr_free_zone_pages(). Because the fallback zonelists contain all nodes in the system, and we walk all the zonelists, we're counting memory multiple times (once for each node). This caused us to make a size estimate of 32GB for an 8GB AMD64 box, which makes all the dirty ratio calculations, etc incorrect. There's still a further bug to fix from e820 holes causing overestimation as well, but this fix is separate, and good as is, and fixes one class of problems. Problem found by Badari, and tested by Ram Pai - thanks! Signed-off-by: Martin J. Bligh <mbligh@mbligh.org> Signed-off-by: Matt Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove bogus warning in page_alloc.cAndy Whitcroft2005-07-27
| | | | | | | | | | | | | | | | | | | | Originally __free_pages_bulk used the relative page number within a zone to define its buddies. This meant that to maintain the "maximally aligned" requirements (that an allocation of size N will be aligned at least to N physically) zones had to also be aligned to 1<<MAX_ORDER pages. When __free_pages_bulk was updated to use the relative page frame numbers of the free'd pages to pair buddies this released the alignment constraint on the 'left' edge of the zone. This allows _either_ edge of the zone to contain partial MAX_ORDER sized buddies. These simply never will have matching buddies and thus will never make it to the 'top' of the pyramid. The patch below removes a now redundant check ensuring that the mem_map was aligned to MAX_ORDER. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <christoph@lameter.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] madvise() does not always return -EBADF on non-file mapped areasuzuki2005-07-27
| | | | | | | | | | | | | | | The madvise() system call returns -EBADF for areas which does not map to files, only for *behaviour* request MADV_WILLNEED. According to man pages, madvise returns : EBADF - the map exists, but the area maps something that isn't a file. Fixes bug 2995. Signed-off-by: Suzuki K P <suzuki@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] check_user_page_readable() deadlock fixAndrew Morton2005-07-27
| | | | | | | | | | | | | | | | | | Fix bug identifued by Richard Purdie <rpurdie@rpsys.net>. oprofile calls check_user_page_readable() from interrupt context, so we deadlock over various VFS locks. But check_user_page_readable() doesn't imply either a read or a write of the page's contents. Change __follow_page() so that check_user_page_readable() can tell __follow_page() that we're not accessing the page's contents, and use that info to avoid the troublesome lock-takings. Also, make follow_page() inline for the single callsite in memory.c to save a bit of stack space. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Undo mempolicy shared policy rbtree microoptimizationAndi Kleen2005-07-27
| | | | | | | | | | | | | | | | | | | | All mempolicy changes must be inside the spinlock and readding the rb_erase prevents a crash while doing: > echo "1" > /tmp/numatest > numactl --length=0x4000 --shm /tmp/numatest --localalloc > numactl --length=0x2000 --offset=0 --shm /tmp/numatest --membind=0 > numactl --length=0x2000 --offset=0x2000 --shm /tmp/numatest --membind=1 > ipcs > ipcrm -M "the_key_value_of_this_shm_area" Based on a patch by John Blackwood Cc: <john.blackwood@ccur.com> Cc: <andrea@suse.de> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] execute-in-place fixesCarsten Otte2005-07-15
| | | | | | | | | | | | | | | | | | | | This patch includes feedback from Andrew and Christoph. Thanks for taking time to review. Use of empty_zero_page was eliminated to fix compilation for architectures that don't have it. This patch removes setting pages up-to-date in ext2_get_xip_page and all bug checks to verify that the page is indeed up to date. Setting the page state on mapping to userland is bogus. None of the code patchs involved with these pages in mm cares about the page state. still on my ToDo list: identify a place outside second extended where __inode_direct_access should reside Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/filemap_xip.c compilation fixGeert Uytterhoeven2005-07-12
| | | | | | | | | | | | | mm/filemap_xip.c: In function `__xip_unmap': mm/filemap_xip.c:194: request for member `pte' in something not a structure or union Apparently pte_pfn() takes a pte_t, not a pointer to a pte_t. From looking at asm/page.h, it seems to be the same on ia32 or ppc (iff STRICT_MM_TYPECHECKS is enabled, which is disabled by default on ppc). Acked-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] propagate __nocast annotationsAlexey Dobriyan2005-07-07
| | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: quieten OOM killer noiseAnton Blanchard2005-07-07
| | | | | | | | | | | | | | | | | We now print statistics when invoking the OOM killer, however this information is not rate limited and you can get into situations where the console is continually spammed. For example, when a task is exiting the OOM killer will simply return (waiting for that task to exit and clear up memory). If the VM continually calls back into the OOM killer we get thousands of copies of show_mem() on the console. Use printk_ratelimit() to quieten it. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove completly bogus comment inside __alloc_pages() ↵Marcelo Tosatti2005-07-07
| | | | | | | | | | | try_to_free_pages handling Remove completly bogus comment from did_some_progress != 0 handling (that same comment is a few lines below on did_some_progress = 0 case, where it belongs). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] print order information when OOM killingMarcelo Tosatti2005-07-07
| | | | | | | Dump the current allocation order when OOM killing. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix broken kmalloc_node in rc1/rc2Christoph Lameter2005-07-06
| | | | | | | | | | | | | | This patch used to be in Andrew's tree before the NUMA slab allocator went in. Either this patch or the NUMA slab allocator is needed in order for kmalloc_node to work correctly. pcibus_to_node may be used to generate the node information passed to kmalloc_node. pcibus_to_node returns -1 if it was not able to determine on which node a pcibus is located. For that case kmalloc_node must work like kmalloc. Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] rename wakeup_bdflush to wakeup_pdflushPekka J Enberg2005-06-29
| | | | | | Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix WANT_PAGE_VIRTUAL in memmap_initBob Picco2005-06-27
| | | | | | | | | | I spotted this issue while in memmap_init last week. I can't say the change has any test coverage by me. start_pfn was formerly used in main "for" loop. The fix is replace start_pfn with pfn. Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge Christoph's freeze cleanup patchLinus Torvalds2005-06-25
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| * [PATCH] Cleanup patch for process freezingChristoph Lameter2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. Establish a simple API for process freezing defined in linux/include/sched.h: frozen(process) Check for frozen process freezing(process) Check if a process is being frozen freeze(process) Tell a process to freeze (go to refrigerator) thaw_process(process) Restart process frozen_process(process) Process is frozen now 2. Remove all references to PF_FREEZE and PF_FROZEN from all kernel sources except sched.h 3. Fix numerous locations where try_to_freeze is manually done by a driver 4. Remove the argument that is no longer necessary from two function calls. 5. Some whitespace cleanup 6. Clear potential race in refrigerator (provides an open window of PF_FREEZE cleared before setting PF_FROZEN, recalc_sigpending does not check PF_FROZEN). This patch does not address the problem of freeze_processes() violating the rule that a task may only modify its own flags by setting PF_FREEZE. This is not clean in an SMP environment. freeze(process) is therefore not SMP safe! Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Use ALIGN to remove duplicate codeNick Wilson2005-06-25
| | | | | | | | | | | | | | | | This patch makes use of ALIGN() to remove duplicate round-up code. Signed-off-by: Nick Wilson <njw@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] kdump: Retrieve saved max pfnVivek Goyal2005-06-25
| | | | | | | | | | | | | | | | | | | | | | This patch retrieves the max_pfn being used by previous kernel and stores it in a safe location (saved_max_pfn) before it is overwritten due to user defined memory map. This pfn is used to make sure that user does not try to read the physical memory beyond saved_max_pfn. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] fix for generic_file_write iov problemBadari Pulavarty2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here is the fix for the problem described in http://bugzilla.kernel.org/show_bug.cgi?id=4721 Basically, problem is generic_file_buffered_write() is accessing beyond end of the iov[] vector after handling the last vector. If we happen to cross page boundary, we get a fault. I think this simple patch is good enough. If we really don't want to depend on the "count", then we need pass nr_segs to filemap_set_next_iovec() and decrement it and check it. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] swsusp: kill config_pm_diskPavel Machek2005-06-25
| | | | | | | | | | | | | | | | | | CONFIG_PM_DISK is long gone, but it still managed to survived at few places. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm: fix remap_pte_range BUGHugh Dickins2005-06-25
| | | | | | | | | | | | | | | | | | | | | | Out-of-tree user of remap_pfn_range hit kernel BUG at mm/memory.c:1112! It passes an unrounded size to remap_pfn_range, which was okay before 2.6.12, but misses remap_pte_range's new end condition. An audit of all the other ptwalks confirms that this is the only one so exposed. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Fix the error handling in direct I/OHifumi Hisashi2005-06-25
|/ | | | | | | | | | | | | | | Fix a bug on error handling in the direct I/O function. Currently, if a file is opened with the O_DIRECT|O_SYNC flag, the write() syscall cannot receive the EIO error after an I/O error (SCSI cable is disconnected etc.). Return values of other points that call generic_osync_inode() are treated appropriately. Signed-off-by: Hisashi Hifumi <hifumi.hisashi@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] xip: madvice/fadvice: execute in placeCarsten Otte2005-06-24
| | | | | | | | Make sys_madvice/fadvice return sane with xip. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] xip: reduce code duplicationCarsten Otte2005-06-24
| | | | | | | | | | | | | | | This patch reworks filemap_xip.c with the goal to reduce code duplication from mm/filemap.c. It applies agains 2.6.12-rc6-mm1. Instead of implementing the aio functions, this one implements the synchronous read/write functions only. For readv and writev, the generic fallback is used. For aio, we rely on the application doing the fallback. Since our "synchronous" function does memcpy immediately anyway, there is no performance difference between using the fallbacks or implementing each operation. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] xip: fs/mm: execute in placeCarsten Otte2005-06-24
| | | | | | | | | | | | | | | | - generic_file* file operations do no longer have a xip/non-xip split - filemap_xip.c implements a new set of fops that require get_xip_page aop to work proper. all new fops are exported GPL-only (don't like to see whatever code use those except GPL modules) - __xip_unmap now uses page_check_address, which is no longer static in rmap.c, and defined in linux/rmap.h - mm/filemap.h is now much more clean, plainly having just Linus' inline funcs moved here from filemap.c - fix includes in filemap_xip to make it build cleanly on i386 Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] DocBook: update commentsMartin Waitz2005-06-24
| | | | | | | | This patch updates some comments to match code changes. Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove f_error field from struct fileChristoph Lameter2005-06-23
| | | | | | | | | | | | | | | | | The following patch removes the f_error field and all checks of f_error. Trond said: f_error was introduced for NFS, and made sense when we were guaranteed always to have a file pointer around when write errors occurred. Since then, we have (for various reasons) had to introduce the nfs_open_context in order to track the file read/write state, and it made sense to move our f_error tracking there too. Signed-off-by: Christoph Lameter <christoph@lameter.com> Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mempool - only init waitqueue in slow pathBenjamin LaHaise2005-06-23
| | | | | | | | | Here's a small patch to improve the performance of mempool_alloc by only initializing the wait queue when we're about to wait. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove redundant vm_flags clearing from madvise.cPekka Enberg2005-06-23
| | | | | | | | | This patch removes redundant VM_ClearReadHint from mm/madvice.c which was left there by Prasanna's patch. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] create a kstrdup library functionPaulo Marques2005-06-23
| | | | | | | | | | | | | | | | This patch creates a new kstrdup library function and changes the "local" implementations in several places to use this function. Most of the changes come from the sound and net subsystems. The sound part had already been acknowledged by Takashi Iwai and the net part by David S. Miller. I left UML alone for now because I would need more time to read the code carefully before making changes there. Signed-off-by: Paulo Marques <pmarques@grupopie.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] NUMA aware block device control structure allocationChristoph Lameter2005-06-23
| | | | | | | | | | | | | | | | Patch to allocate the control structures for for ide devices on the node of the device itself (for NUMA systems). The patch depends on the Slab API change patch by Manfred and me (in mm) and the pcidev_to_node patch that I posted today. Does some realignment too. Signed-off-by: Justin M. Forbes <jmforbes@linuxtx.org> Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Pravin Shelar <pravin@calsoftinc.com> Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem hotplug baseAndy Whitcroft2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sparse's initalization be accessible at runtime. This allows sparse mappings to be created after boot in a hotplug situation. This patch is separated from the previous one just to give an indication how much of the sparse infrastructure is *just* for hotplug memory. The section_mem_map doesn't really store a pointer. It stores something that is convenient to do some math against to get a pointer. It isn't valid to just do *section_mem_map, so I don't think it should be stored as a pointer. There are a couple of things I'd like to store about a section. First of all, the fact that it is !NULL does not mean that it is present. There could be such a combination where section_mem_map *is* NULL, but the math gets you properly to a real mem_map. So, I don't think that check is safe. Since we're storing 32-bit-aligned structures, we have a few bits in the bottom of the pointer to play with. Use one bit to encode whether there's really a mem_map there, and the other one to tell whether there's a valid section there. We need to distinguish between the two because sometimes there's a gap between when a section is discovered to be present and when we can get the mem_map for it. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem swiss cheese numa layoutsAndy Whitcroft2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The part of the sparsemem patch which modifies memmap_init_zone() has recently become a problem. It changes behavior so that there is a call to pfn_to_page() for each individual page inside of a node's range: node_start_pfn through node_end_pfn. It used to simply do this once, at the beginning of the node, but having sparsemem's non-contiguous mem_map[]s inside of a node made it necessary to change. Mike Kravetz recently wrote a patch which made the NUMA code accept some new kinds of layouts. The system's memory was laid out like this, with node 0's memory in two pieces: one before and one after node 1's memory: Node 0: +++++ +++++ Node 1: +++++ Previous behavior before Mike's patch was to assign nodes like this: Node 0: 00000 XXXXX Node 1: 11111 Where the 'X' areas were simply thrown away. The new behavior was to make the pg_data_t span node 0 across all of its areas, including areas that are really node 1's: Node 0: 000000000000000 Node 1: 11111 This wastes a little bit of mem_map space, but ends up being OK, and more fully utilizes the system's memory. memmap_init_zone() initializes all of the "struct page"s for node 0, even for the "hole", but those never get used, because there is no pfn_to_page() that resolves to those pages. However, only calling pfn_to_page() once, memmap_init_zone() always uses the pages that were allocated for node0->node_mem_map because: struct page *start = pfn_to_page(start_pfn); // effectively start = &node->node_mem_map[0] for (page = start; page < (start + size); page++) { init_page_here();... page++; } Slow, and wasteful, but generally harmless. But, modify that to call pfn_to_page() for each loop iteration (like sparsemem does): for (pfn = start_pfn; pfn < < (start_pfn + size); pfn++++) { page = pfn_to_page(pfn); } And you end up trying to initialize node 1's pages too early, along with bogus data from node 0. This patch checks for those weird layouts and declines to touch the pages, making the more frequent pfn_to_page() calls OK to do. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem memory modelAndy Whitcroft2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparsemem abstracts the use of discontiguous mem_maps[]. This kind of mem_map[] is needed by discontiguous memory machines (like in the old CONFIG_DISCONTIGMEM case) as well as memory hotplug systems. Sparsemem replaces DISCONTIGMEM when enabled, and it is hoped that it can eventually become a complete replacement. A significant advantage over DISCONTIGMEM is that it's completely separated from CONFIG_NUMA. When producing this patch, it became apparent in that NUMA and DISCONTIG are often confused. Another advantage is that sparse doesn't require each NUMA node's ranges to be contiguous. It can handle overlapping ranges between nodes with no problems, where DISCONTIGMEM currently throws away that memory. Sparsemem uses an array to provide different pfn_to_page() translations for each SECTION_SIZE area of physical memory. This is what allows the mem_map[] to be chopped up. In order to do quick pfn_to_page() operations, the section number of the page is encoded in page->flags. Part of the sparsemem infrastructure enables sharing of these bits more dynamically (at compile-time) between the page_zone() and sparsemem operations. However, on 32-bit architectures, the number of bits is quite limited, and may require growing the size of the page->flags type in certain conditions. Several things might force this to occur: a decrease in the SECTION_SIZE (if you want to hotplug smaller areas of memory), an increase in the physical address space, or an increase in the number of used page->flags. One thing to note is that, once sparsemem is present, the NUMA node information no longer needs to be stored in the page->flags. It might provide speed increases on certain platforms and will be stored there if there is room. But, if out of room, an alternate (theoretically slower) mechanism is used. This patch introduces CONFIG_FLATMEM. It is used in almost all cases where there used to be an #ifndef DISCONTIG, because SPARSEMEM and DISCONTIGMEM often have to compile out the same areas of code. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Martin Bligh <mbligh@aracnet.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] generify memory presentAndy Whitcroft2005-06-23
| | | | | | | | | | | | Allow architectures to indicate that they will be providing hooks to indice installed memory areas, memory_present(). Provide prototypes for the i386 implementation. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Martin Bligh <mbligh@aracnet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/Kconfig: give DISCONTIG more help textDave Hansen2005-06-23
| | | | | | | | | This gives DISCONTIGMEM a bit more help text to explain what it does, not just when to choose it. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/Kconfig: hide "Memory Model" selection menuDave Hansen2005-06-23
| | | | | | | | | | | | | I got some feedback from users who think that the new "Memory Model" menu is a little invasive. This patch will hide that menu, except when CONFIG_EXPERIMENTAL is enabled *or* when an individual architecture wants it. An individual arch may want to enable it because they've removed their arch-specific DISCONTIG prompt in favor of the mm/Kconfig one. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem: fix minor "defaults" issue in mm/KconfigDave Hansen2005-06-23
| | | | | | | | | | | | The following patch applies on top of 2.6.12-rc2-mm1. It fixes a minor user interaction issue, and an early reference to SPARSEMEM. This "choice" menu would always default to FLATMEM, as it was listed first. Move it to the end so that the other defaults have a chance first. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Introduce new Kconfig option for NUMA or DISCONTIGDave Hansen2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There is some confusion that arose when working on SPARSEMEM patch between what is needed for DISCONTIG vs. NUMA. Multiple pg_data_t's are needed for DISCONTIGMEM or NUMA, independently. All of the current NUMA implementations require an implementation of DISCONTIG. Because of this, quite a lot of code which is really needed for NUMA is actually under DISCONTIG #ifdefs. For SPARSEMEM, we changed some of these #ifdefs to CONFIG_NUMA, but that broke the DISCONTIG=y and NUMA=n case. Introducing this new NEED_MULTIPLE_NODES config option allows code that is needed for both NUMA or DISCONTIG to be separated out from code that is specific to DISCONTIG. One great advantage of this approach is that it doesn't require every architecture to be converted over. All of the current implementations should "just work", only the ones implementing SPARSEMEM will have to be fixed up. The change to free_area_init() makes it work inside, or out of the new config option. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] create mm/Kconfig for arch-independent memory optionsDave Hansen2005-06-23
| | | | | | | | | | | | | | | | | | | | With sparsemem being introduced, we need a central place for new memory-related .config options: mm/Kconfig. This allows us to remove many of the duplicated arch-specific options. The new option, CONFIG_FLATMEM, is there to enable us to detangle NUMA and DISCONTIGMEM. This is a requirement for sparsemem because sparsemem uses the NUMA code without the presence of DISCONTIGMEM. The sparsemem patches use CONFIG_FLATMEM in generic code, so this patch is a requirement before applying them. Almost all places that used to do '#ifndef CONFIG_DISCONTIGMEM' should use '#ifdef CONFIG_FLATMEM' instead. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem base: reorganize page->flags bit operationsDave Hansen2005-06-23
| | | | | | | | | | | | Generify the value fields in the page_flags. The aim is to allow the location and size of these fields to be varied. Additionally we want to move away from fixed allocations per field whilst still enforcing the overall bit utilisation limits. We rely on the compiler to spot and optimise the accessor functions. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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