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* mm: fault feedback #1Nick Piggin2007-07-197-398/+122
| | | | | | | | | | | | | | | | | | | | | | | | Change ->fault prototype. We now return an int, which contains VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte. FAULT_RET_ code tells the VM whether a page was found, whether it has been locked, and potentially other things. This is not quite the way he wanted it yet, but that's changed in the next patch (which requires changes to arch code). This means we no longer set VM_CAN_INVALIDATE in the vma in order to say that a page is locked which requires filemap_nopage to go away (because we can no longer remain backward compatible without that flag), but we were going to do that anyway. struct fault_data is renamed to struct vm_fault as Linus asked. address is now a void __user * that we should firmly encourage drivers not to use without really good reason. The page is now returned via a page pointer in the vm_fault struct. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ocfs2: release page lock before calling ->page_mkwriteMark Fasheh2007-07-191-5/+9
| | | | | | | | | | | | __do_fault() was calling ->page_mkwrite() with the page lock held, which violates the locking rules for that callback. Release and retake the page lock around the callback to avoid deadlocking file systems which manually take it. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.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: merge populate and nopage into fault (fixes nonlinear)Nick Piggin2007-07-199-209/+273
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes the virtual address -> file offset differently from linear mappings. ->populate is a layering violation because the filesystem/pagecache code should need to know anything about the virtual memory mapping. The hitch here is that the ->nopage handler didn't pass down enough information (ie. pgoff). But it is more logical to pass pgoff rather than have the ->nopage function calculate it itself anyway (because that's a similar layering violation). Having the populate handler install the pte itself is likewise a nasty thing to be doing. This patch introduces a new fault handler that replaces ->nopage and ->populate and (later) ->nopfn. Most of the old mechanism is still in place so there is a lot of duplication and nice cleanups that can be removed if everyone switches over. The rationale for doing this in the first place is that nonlinear mappings are subject to the pagefault vs invalidate/truncate race too, and it seemed stupid to duplicate the synchronisation logic rather than just consolidate the two. After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in pagecache. Seems like a fringe functionality anyway. NOPAGE_REFAULT is removed. This should be implemented with ->fault, and no users have hit mainline yet. [akpm@linux-foundation.org: cleanup] [randy.dunlap@oracle.com: doc. fixes for readahead] [akpm@linux-foundation.org: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix fault vs invalidate race for linear mappingsNick Piggin2007-07-194-116/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the race between invalidate_inode_pages and do_no_page. Andrea Arcangeli identified a subtle race between invalidation of pages from pagecache with userspace mappings, and do_no_page. The issue is that invalidation has to shoot down all mappings to the page, before it can be discarded from the pagecache. Between shooting down ptes to a particular page, and actually dropping the struct page from the pagecache, do_no_page from any process might fault on that page and establish a new mapping to the page just before it gets discarded from the pagecache. The most common case where such invalidation is used is in file truncation. This case was catered for by doing a sort of open-coded seqlock between the file's i_size, and its truncate_count. Truncation will decrease i_size, then increment truncate_count before unmapping userspace pages; do_no_page will read truncate_count, then find the page if it is within i_size, and then check truncate_count under the page table lock and back out and retry if it had subsequently been changed (ptl will serialise against unmapping, and ensure a potentially updated truncate_count is actually visible). Complexity and documentation issues aside, the locking protocol fails in the case where we would like to invalidate pagecache inside i_size. do_no_page can come in anytime and filemap_nopage is not aware of the invalidation in progress (as it is when it is outside i_size). The end result is that dangling (->mapping == NULL) pages that appear to be from a particular file may be mapped into userspace with nonsense data. Valid mappings to the same place will see a different page. Andrea implemented two working fixes, one using a real seqlock, another using a page->flags bit. He also proposed using the page lock in do_no_page, but that was initially considered too heavyweight. However, it is not a global or per-file lock, and the page cacheline is modified in do_no_page to increment _count and _mapcount anyway, so a further modification should not be a large performance hit. Scalability is not an issue. This patch implements this latter approach. ->nopage implementations return with the page locked if it is possible for their underlying file to be invalidated (in that case, they must set a special vm_flags bit to indicate so). do_no_page only unlocks the page after setting up the mapping completely. invalidation is excluded because it holds the page lock during invalidation of each page (and ensures that the page is not mapped while holding the lock). This also allows significant simplifications in do_no_page, because we have the page locked in the right place in the pagecache from the start. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Allocate and free vmalloc areasJeremy Fitzhardinge2007-07-181-0/+53
| | | | | | | | | | | | | | | Allocate/release a chunk of vmalloc address space: alloc_vm_area reserves a chunk of address space, and makes sure all the pagetables are constructed for that address range - but no pages. free_vm_area releases the address space range. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ian Pratt <ian.pratt@xensource.com> Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: "Jan Beulich" <JBeulich@novell.com> Cc: "Andi Kleen" <ak@muc.de>
* add kstrndupJeremy Fitzhardinge2007-07-181-2/+24
| | | | | | | | | | | | | | | | | | | Add a kstrndup function, modelled on strndup. Like strndup this returns a string copied into its own allocated memory, but it copies no more than the specified number of bytes from the source. Remove private strndup() from irda code. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@mandriva.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Panagiotis Issaris <takis@issaris.org> Cc: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
* knfsd: nfsd4: vary maximum delegation limit based on RAM sizeMeelap Shah2007-07-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Our original NFSv4 delegation policy was to give out a read delegation on any open when it was possible to. Since the lifetime of a delegation isn't limited to that of an open, a client may quite reasonably hang on to a delegation as long as it has the inode cached. This becomes an obvious problem the first time a client's inode cache approaches the size of the server's total memory. Our first quick solution was to add a hard-coded limit. This patch makes a mild incremental improvement by varying that limit according to the server's total memory size, allowing at most 4 delegations per megabyte of RAM. My quick back-of-the-envelope calculation finds that in the worst case (where every delegation is for a different inode), a delegation could take about 1.5K, which would make the worst case usage about 6% of memory. The new limit works out to be about the same as the old on a 1-gig server. [akpm@linux-foundation.org: Don't needlessly bloat vmlinux] [akpm@linux-foundation.org: Make it right for highmem machines] Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* knfsd: exportfs: add exportfs.h headerChristoph Hellwig2007-07-171-0/+1
| | | | | | | | | | | | | currently the export_operation structure and helpers related to it are in fs.h. fs.h is already far too large and there are very few places needing the export bits, so split them off into a separate header. [akpm@linux-foundation.org: fix cifs build] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@suse.de> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kallsyms: make KSYM_NAME_LEN include space for trailing '\0'Tejun Heo2007-07-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | KSYM_NAME_LEN is peculiar in that it does not include the space for the trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating buffer. This is nonsense and error-prone. Moreover, when the caller forgets that it's very likely to subtly bite back by corrupting the stack because the last position of the buffer is always cleared to zero. This patch increments KSYM_NAME_LEN by one and updates code accordingly. * off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro is fixed. * Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together, MODULE_NAME_LEN was treated as if it didn't include space for the trailing '\0'. Fix it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.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>
* CONFIG_BOUNCE to avoid useless inclusion of bounce buffer logicChristoph Lameter2007-07-172-3/+5
| | | | | | | | | | | | | | The bounce buffer logic is included on systems that do not need it. If a system does not have zones like ZONE_DMA and ZONE_HIGHMEM that can lead to the use of bounce buffers then there is no need to reserve memory pools etc etc. This is true f.e. for SGI Altix. Also nicifies the Makefile and gets rid of the tricky "and" there. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Freezer: make kernel threads nonfreezable by defaultRafael J. Wysocki2007-07-172-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the freezer treats all tasks as freezable, except for the kernel threads that explicitly set the PF_NOFREEZE flag for themselves. This approach is problematic, since it requires every kernel thread to either set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't care for the freezing of tasks at all. It seems better to only require the kernel threads that want to or need to be frozen to use some freezer-related code and to remove any freezer-related code from the other (nonfreezable) kernel threads, which is done in this patch. The patch causes all kernel threads to be nonfreezable by default (ie. to have PF_NOFREEZE set by default) and introduces the set_freezable() function that should be called by the freezable kernel threads in order to unset PF_NOFREEZE. It also makes all of the currently freezable kernel threads call set_freezable(), so it shouldn't cause any (intentional) change of behaviour to appear. Additionally, it updates documentation to describe the freezing of tasks more accurately. [akpm@linux-foundation.org: build fixes] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: introduce some page/buffer invariantsNick Piggin2007-07-172-1/+2
| | | | | | | | | | | | | | | | | | | | | | It is a bug to set a page dirty if it is not uptodate unless it has buffers. If the page has buffers, then the page may be dirty (some buffers dirty) but not uptodate (some buffers not uptodate). The exception to this rule is if the set_page_dirty caller is racing with truncate or invalidate. A buffer can not be set dirty if it is not uptodate. If either of these situations occurs, it indicates there could be some data loss problem. Some of these warnings could be a harmless one where the page or buffer is set uptodate immediately after it is dirtied, however we should fix those up, and enforce this ordering. Bring the order of operations for truncate into line with those of invalidate. This will prevent a page from being able to go !uptodate while we're holding the tree_lock, which is probably a good thing anyway. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* MM: Make needlessly global hugetlb_no_page() static.Robert P. J. Day2007-07-171-1/+1
| | | | | | Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Fix CONFIG_SLUB_DEBUG use for CONFIG_NUMAChristoph Lameter2007-07-171-0/+4
| | | | | | | | | | | | We currently cannot disable CONFIG_SLUB_DEBUG for CONFIG_NUMA. Now that embedded systems start to use NUMA we may need this. Put an #ifdef around places where NUMA only code uses fields only valid for CONFIG_SLUB_DEBUG. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Move sysfs operations outside of slub_lockChristoph Lameter2007-07-171-13/+15
| | | | | | | | | | | | | | | Sysfs can do a gazillion things when called. Make sure that we do not call any sysfs functions while holding the slub_lock. Just protect the essentials: 1. The list of all slab caches 2. The kmalloc_dma array 3. The ref counters of the slabs. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Do not allocate object bit array on stackChristoph Lameter2007-07-171-14/+25
| | | | | | | | | | | | | | The objects per slab increase with the current patches in mm since we allow up to order 3 allocs by default. More patches in mm actually allow to use 2M or higher sized slabs. For slab validation we need per object bitmaps in order to check a slab. We end up with up to 64k objects per slab resulting in a potential requirement of 8K stack space. That does not look good. Allocate the bit arrays via kmalloc. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Slab allocators: Replace explicit zeroing with __GFP_ZEROChristoph Lameter2007-07-173-11/+7
| | | | | | | | | | | | | kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing variant in the past. But with __GFP_ZERO it is possible now to do zeroing while allocating. Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever we can. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Slab allocators: Cleanup zeroing allocationsChristoph Lameter2007-07-174-52/+0
| | | | | | | | | | | It becomes now easy to support the zeroing allocs with generic inline functions in slab.h. Provide inline definitions to allow the continued use of kzalloc, kmem_cache_zalloc etc but remove other definitions of zeroing functions from the slab allocators and util.c. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Do not use length parameter in slab_alloc()Christoph Lameter2007-07-171-11/+9
| | | | | | | | | | We can get to the length of the object through the kmem_cache_structure. The additional parameter does no good and causes the compiler to generate bad code. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Style fix up the loop to disable small slabsChristoph Lameter2007-07-171-1/+1
| | | | | | | | Do proper spacing and we only need to do this in steps of 8. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/slub.c: make code staticAdrian Bunk2007-07-171-3/+3
| | | | | | | Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Simplify dma index -> size calculationChristoph Lameter2007-07-171-9/+1
| | | | | | | | | There is no need to caculate the dma slab size ourselves. We can simply lookup the size of the corresponding non dma slab. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: faster more efficient slab determination for __kmallocChristoph Lameter2007-07-171-7/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmalloc_index is a long series of comparisons. The attempt to replace kmalloc_index with something more efficient like ilog2 failed due to compiler issues with constant folding on gcc 3.3 / powerpc. kmalloc_index()'es long list of comparisons works fine for constant folding since all the comparisons are optimized away. However, SLUB also uses kmalloc_index to determine the slab to use for the __kmalloc_xxx functions. This leads to a large set of comparisons in get_slab(). The patch here allows to get rid of that list of comparisons in get_slab(): 1. If the requested size is larger than 192 then we can simply use fls to determine the slab index since all larger slabs are of the power of two type. 2. If the requested size is smaller then we cannot use fls since there are non power of two caches to be considered. However, the sizes are in a managable range. So we divide the size by 8. Then we have only 24 possibilities left and then we simply look up the kmalloc index in a table. Code size of slub.o decreases by more than 200 bytes through this patch. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: do proper locking during dma slab creationChristoph Lameter2007-07-171-2/+9
| | | | | | | | | | We modify the kmalloc_cache_dma[] array without proper locking. Do the proper locking and undo the dma cache creation if another processor has already created it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: extract dma_kmalloc_cache from get_cache.Christoph Lameter2007-07-171-30/+36
| | | | | | | | | | | The rarely used dma functionality in get_slab() makes the function too complex. The compiler begins to spill variables from the working set onto the stack. The created function is only used in extremely rare cases so make sure that the compiler does not decide on its own to merge it back into get_slab(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: add some more inlines and #ifdef CONFIG_SLUB_DEBUGChristoph Lameter2007-07-171-6/+7
| | | | | | | | | | | Add #ifdefs around data structures only needed if debugging is compiled into SLUB. Add inlines to small functions to reduce code size. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Slab allocators: support __GFP_ZERO in all allocatorsChristoph Lameter2007-07-173-10/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A kernel convention for many allocators is that if __GFP_ZERO is passed to an allocator then the allocated memory should be zeroed. This is currently not supported by the slab allocators. The inconsistency makes it difficult to implement in derived allocators such as in the uncached allocator and the pool allocators. In addition the support zeroed allocations in the slab allocators does not have a consistent API. There are no zeroing allocator functions for NUMA node placement (kmalloc_node, kmem_cache_alloc_node). The zeroing allocations are only provided for default allocs (kzalloc, kmem_cache_zalloc_node). __GFP_ZERO will make zeroing universally available and does not require any addititional functions. So add the necessary logic to all slab allocators to support __GFP_ZERO. The code is added to the hot path. The gfp flags are on the stack and so the cacheline is readily available for checking if we want a zeroed object. Zeroing while allocating is now a frequent operation and we seem to be gradually approaching a 1-1 parity between zeroing and not zeroing allocs. The current tree has 3476 uses of kmalloc vs 2731 uses of kzalloc. Signed-off-by: Christoph Lameter <clameter@sgi.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>
* Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semanticsChristoph Lameter2007-07-174-23/+32
| | | | | | | | | | | | | | | | Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the allocators. Move ZERO_SIZE_PTR related stuff into slab.h. Make ZERO_SIZE_PTR work for all slab allocators and get rid of the WARN_ON_ONCE(size == 0) that is still remaining in SLAB. Make slub return NULL like the other allocators if a too large memory segment is requested via __kmalloc. Signed-off-by: Christoph Lameter <clameter@sgi.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>
* Slab allocators: consolidate code for krealloc in mm/util.cChristoph Lameter2007-07-174-116/+34
| | | | | | | | | | | | | | The size of a kmalloc object is readily available via ksize(). ksize is provided by all allocators and thus we can implement krealloc in a generic way. Implement krealloc in mm/util.c and drop slab specific implementations of krealloc. Signed-off-by: Christoph Lameter <clameter@sgi.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>
* SLUB Debug: fix initial object debug state of NUMA bootstrap objectsChristoph Lameter2007-07-171-1/+2
| | | | | | | | | | | | | The function we are calling to initialize object debug state during early NUMA bootstrap sets up an inactive object giving it the wrong redzone signature. The bootstrap nodes are active objects and should have active redzone signatures. Currently slab validation complains and reverts the object to active state. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: ensure that the number of objects per slab stays low for high ordersChristoph Lameter2007-07-171-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | Currently SLUB has no provision to deal with too high page orders that may be specified on the kernel boot line. If an order higher than 6 (on a 4k platform) is generated then we will BUG() because slabs get more than 65535 objects. Add some logic that decreases order for slabs that have too many objects. This allow booting with slab sizes up to MAX_ORDER. For example slub_min_order=10 will boot with a default slab size of 4M and reduce slab sizes for small object sizes to lower orders if the number of objects becomes too big. Large slab sizes like that allow a concentration of objects of the same slab cache under as few as possible TLB entries and thus potentially reduces TLB pressure. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB slab validation: Move tracking information alloc outside of lockChristoph Lameter2007-07-171-10/+7
| | | | | | | | | | | | | | | | We currently have to do an GFP_ATOMIC allocation because the list_lock is already taken when we first allocate memory for tracking allocation information. It would be better if we could avoid atomic allocations. Allocate a size of the tracking table that is usually sufficient (one page) before we take the list lock. We will then only do the atomic allocation if we need to resize the table to become larger than a page (mostly only needed under large NUMA because of the tracking of cpus and nodes otherwise the table stays small). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: use list_for_each_entry for loops over all slabsChristoph Lameter2007-07-171-38/+13
| | | | | | | | | | | Use list_for_each_entry() instead of list_for_each(). Get rid of for_all_slabs(). It had only one user. So fold it into the callback. This also gets rid of cpu_slab_flush. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: change error reporting format to follow lockdep looselyChristoph Lameter2007-07-171-123/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes the error reporting format to loosely follow lockdep. If data corruption is detected then we generate the following lines: ============================================ BUG <slab-cache>: <problem> -------------------------------------------- INFO: <more information> [possibly multiple times] <object dump> FIX <slab-cache>: <remedial action> This also adds some more intelligence to the data corruption detection. Its now capable of figuring out the start and end. Add a comment on how to configure SLUB so that a production system may continue to operate even though occasional slab corruption occur through a misbehaving kernel component. See "Emergency operations" in Documentation/vm/slub.txt. [akpm@linux-foundation.org: build fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: clean up and kernelify shrinker registrationRusty Russell2007-07-171-31/+11
| | | | | | | | | | | | | | | | | | | I can never remember what the function to register to receive VM pressure is called. I have to trace down from __alloc_pages() to find it. It's called "set_shrinker()", and it needs Your Help. 1) Don't hide struct shrinker. It contains no magic. 2) Don't allocate "struct shrinker". It's not helpful. 3) Call them "register_shrinker" and "unregister_shrinker". 4) Call the function "shrink" not "shrinker". 5) Reduce the 17 lines of waffly comments to 13, but document it properly. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: David Chinner <dgc@sgi.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Lumpy Reclaim V4Andy Whitcroft2007-07-172-24/+152
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are out of memory of a suitable size we enter reclaim. The current reclaim algorithm targets pages in LRU order, which is great for fairness at order-0 but highly unsuitable if you desire pages at higher orders. To get pages of higher order we must shoot down a very high proportion of memory; >95% in a lot of cases. This patch set adds a lumpy reclaim algorithm to the allocator. It targets groups of pages at the specified order anchored at the end of the active and inactive lists. This encourages groups of pages at the requested orders to move from active to inactive, and active to free lists. This behaviour is only triggered out of direct reclaim when higher order pages have been requested. This patch set is particularly effective when utilised with an anti-fragmentation scheme which groups pages of similar reclaimability together. This patch set is based on Peter Zijlstra's lumpy reclaim V2 patch which forms the foundation. Credit to Mel Gorman for sanitity checking. Mel said: The patches have an application with hugepage pool resizing. When lumpy-reclaim is used used with ZONE_MOVABLE, the hugepages pool can be resized with greater reliability. Testing on a desktop machine with 2GB of RAM showed that growing the hugepage pool with ZONE_MOVABLE on it's own was very slow as the success rate was quite low. Without lumpy-reclaim, each attempt to grow the pool by 100 pages would yield 1 or 2 hugepages. With lumpy-reclaim, getting 40 to 70 hugepages on each attempt was typical. [akpm@osdl.org: ia64 pfn_to_nid fixes and loop cleanup] [bunk@stusta.de: static declarations for internal functions] [a.p.zijlstra@chello.nl: initial lumpy V2 implementation] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add a movablecore= parameter for sizing ZONE_MOVABLEMel Gorman2007-07-171-7/+58
| | | | | | | | | | | | | | | | | | | | | | This patch adds a new parameter for sizing ZONE_MOVABLE called movablecore=. While kernelcore= is used to specify the minimum amount of memory that must be available for all allocation types, movablecore= is used to specify the minimum amount of memory that is used for migratable allocations. The amount of memory used for migratable allocations determines how large the huge page pool could be dynamically resized to at runtime for example. How movablecore is actually handled is that the total number of pages in the system is calculated and a value is set for kernelcore that is kernelcore == totalpages - movablecore Both kernelcore= and movablecore= can be safely specified at the same time. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* handle kernelcore=: genericMel Gorman2007-07-171-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the kernelcore= parameter for x86. Once all patches are applied, a new command-line parameter exist and a new sysctl. This patch adds the necessary documentation. From: Yasunori Goto <y-goto@jp.fujitsu.com> When "kernelcore" boot option is specified, kernel can't boot up on ia64 because of an infinite loop. In addition, the parsing code can be handled in an architecture-independent manner. This patch uses common code to handle the kernelcore= parameter. It is only available to architectures that support arch-independent zone-sizing (i.e. define CONFIG_ARCH_POPULATES_NODE_MAP). Other architectures will ignore the boot parameter. [bunk@stusta.de: make cmdline_parse_kernelcore() static] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Allow huge page allocations to use GFP_HIGH_MOVABLEMel Gorman2007-07-172-5/+23
| | | | | | | | | | | | | | | | | | | Huge pages are not movable so are not allocated from ZONE_MOVABLE. However, as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it can be used to satisfy hugepage allocations even when the system has been running a long time. This allows an administrator to resize the hugepage pool at runtime depending on the size of ZONE_MOVABLE. This patch adds a new sysctl called hugepages_treat_as_movable. When a non-zero value is written to it, future allocations for the huge page pool will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not introduce additional external fragmentation of note as huge pages are always the largest contiguous block we care about. [akpm@linux-foundation.org: various fixes] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Create the ZONE_MOVABLE zoneMel Gorman2007-07-173-6/+235
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following 8 patches against 2.6.20-mm2 create a zone called ZONE_MOVABLE that is only usable by allocations that specify both __GFP_HIGHMEM and __GFP_MOVABLE. This has the effect of keeping all non-movable pages within a single memory partition while allowing movable allocations to be satisfied from either partition. The patches may be applied with the list-based anti-fragmentation patches that groups pages together based on mobility. The size of the zone is determined by a kernelcore= parameter specified at boot-time. This specifies how much memory is usable by non-movable allocations and the remainder is used for ZONE_MOVABLE. Any range of pages within ZONE_MOVABLE can be released by migrating the pages or by reclaiming. When selecting a zone to take pages from for ZONE_MOVABLE, there are two things to consider. First, only memory from the highest populated zone is used for ZONE_MOVABLE. On the x86, this is probably going to be ZONE_HIGHMEM but it would be ZONE_DMA on ppc64 or possibly ZONE_DMA32 on x86_64. Second, the amount of memory usable by the kernel will be spread evenly throughout NUMA nodes where possible. If the nodes are not of equal size, the amount of memory usable by the kernel on some nodes may be greater than others. By default, the zone is not as useful for hugetlb allocations because they are pinned and non-migratable (currently at least). A sysctl is provided that allows huge pages to be allocated from that zone. This means that the huge page pool can be resized to the size of ZONE_MOVABLE during the lifetime of the system assuming that pages are not mlocked. Despite huge pages being non-movable, we do not introduce additional external fragmentation of note as huge pages are always the largest contiguous block we care about. Credit goes to Andy Whitcroft for catching a large variety of problems during review of the patches. This patch creates an additional zone, ZONE_MOVABLE. This zone is only usable by allocations which specify both __GFP_HIGHMEM and __GFP_MOVABLE. Hot-added memory continues to be placed in their existing destination as there is no mechanism to redirect them to a specific zone. [y-goto@jp.fujitsu.com: Fix section mismatch of memory hotplug related code] [akpm@linux-foundation.org: various fixes] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add __GFP_MOVABLE for callers to flag allocations from high memory that may ↵Mel Gorman2007-07-175-10/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | be migrated It is often known at allocation time whether a page may be migrated or not. This patch adds a flag called __GFP_MOVABLE and a new mask called GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated using the page migration mechanism or reclaimed by syncing with backing storage and discarding. An API function very similar to alloc_zeroed_user_highpage() is added for __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The flags used by alloc_zeroed_user_highpage() are not changed because it would change the semantics of an existing API. After this patch is applied there are no in-kernel users of alloc_zeroed_user_highpage() so it probably should be marked deprecated if this patch is merged. Note that this patch includes a minor cleanup to the use of __GFP_ZERO in shmem.c to keep all flag modifications to inode->mapping in the shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of Hugh Dickens. Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the concept. Credit to Hugh Dickens for catching issues with shmem swap vector and ramfs allocations. [akpm@linux-foundation.org: build fix] [hugh@veritas.com: __GFP_ZERO cleanup] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix read/truncate raceNeilBrown2007-07-171-44/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_generic_mapping_read currently samples the i_size at the start and doesn't do so again unless it needs to call ->readpage to load a page. After ->readpage it has to re-sample i_size as a truncate may have caused that page to be filled with zeros, and the read() call should not see these. However there are other activities that might cause ->readpage to be called on a page between the time that do_generic_mapping_read samples i_size and when it finds that it has an uptodate page. These include at least read-ahead and possibly another thread performing a read. So do_generic_mapping_read must sample i_size *after* it has an uptodate page. Thus the current sampling at the start and after a read can be replaced with a sampling before the copy-out. The same change applied to __generic_file_splice_read. Note that this fixes any race with truncate_complete_page, but does not fix a possible race with truncate_partial_page. If a partial truncate happens after do_generic_mapping_read samples i_size and before the copy_out, the nuls that truncate_partial_page place in the page could be copied out incorrectly. I think the best fix for that is to *not* zero out parts of the page in truncate_partial_page, but rather to zero out the tail of a page when increasing i_size. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Jens Axboe <jens.axboe@oracle.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'merge' of ↵Linus Torvalds2007-07-161-4/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (209 commits) [POWERPC] Create add_rtc() function to enable the RTC CMOS driver [POWERPC] Add H_ILLAN_ATTRIBUTES hcall number [POWERPC] xilinxfb: Parameterize xilinxfb platform device registration [POWERPC] Oprofile support for Power 5++ [POWERPC] Enable arbitary speed tty ioctls and split input/output speed [POWERPC] Make drivers/char/hvc_console.c:khvcd() static [POWERPC] Remove dead code for preventing pread() and pwrite() calls [POWERPC] Remove unnecessary #undef printk from prom.c [POWERPC] Fix typo in Ebony default DTS [POWERPC] Check for NULL ppc_md.init_IRQ() before calling [POWERPC] Remove extra return statement [POWERPC] pasemi: Don't auto-select CONFIG_EMBEDDED [POWERPC] pasemi: Rename platform [POWERPC] arch/powerpc/kernel/sysfs.c: Move NUMA exports [POWERPC] Add __read_mostly support for powerpc [POWERPC] Modify sched_clock() to make CONFIG_PRINTK_TIME more sane [POWERPC] Create a dummy zImage if no valid platform has been selected [POWERPC] PS3: Bootwrapper support. [POWERPC] powermac i2c: Use mutex [POWERPC] Schedule removal of arch/ppc ... Fixed up conflicts manually in: Documentation/feature-removal-schedule.txt arch/powerpc/kernel/pci_32.c arch/powerpc/kernel/pci_64.c include/asm-powerpc/pci.h and asked the powerpc people to double-check the result..
| * Merge branch 'for-2.6.23' into mergePaul Mackerras2007-07-111-4/+9
| |\
| | * [POWERPC] unmap_vm_area becomes unmap_kernel_range for the publicBenjamin Herrenschmidt2007-06-141-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes unmap_vm_area static and a wrapper around a new exported unmap_kernel_range that takes an explicit range instead of a vm_area struct. This makes it more versatile for code that wants to play with kernel page tables outside of the standard vmalloc area. (One example is some rework of the PowerPC PCI IO space mapping code that depends on that patch and removes some code duplication and horrible abuse of forged struct vm_struct). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | | Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6Linus Torvalds2007-07-161-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6: (68 commits) sh: sh-rtc support for SH7709. sh: Revert __xdiv64_32 size change. sh: Update r7785rp defconfig. sh: Export div symbols for GCC 4.2 and ST GCC. sh: fix race in parallel out-of-tree build sh: Kill off dead mach.c for hp6xx. sh: hd64461.h cleanup and added comments. sh: Update the alignment when 4K stacks are used. sh: Add a .bss.page_aligned section for 4K stacks. sh: Don't let SH-4A clobber SH-4 CFLAGS. sh: Add parport stub for SuperIO ports. sh: Drop -Wa,-dsp for DSP tuning. sh: Update dreamcast defconfig. fb: pvr2fb: A few more __devinit annotations for PCI. fb: pvr2fb: Fix up section mismatch warnings. sh: Select IPR-IRQ for SH7091. sh: Correct __xdiv64_32/div64_32 return value size. sh: Fix timer-tmu build for SH-3. sh: Add cpu and mach links to CLEAN_FILES. sh: Preliminary support for the SH-X3 CPU. ...
| * | | sh: memory hot-add for sparsemem users support.Paul Mundt2007-06-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables simple hotplug support for sparsemem users. Presently this only permits memory being added in to node 0 on ZONE_NORMAL. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* | | | permit mempool_free(NULL)Rusty Russell2007-07-161-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christian Borntraeger points out that mempool_free() doesn't noop when handed NULL. This is inconsistent with the other free-like functions in the kernel. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | remove mm/backing-dev.c:congestion_wait_interruptible()Adrian Bunk2007-07-161-16/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | congestion_wait_interruptible() is no longer used. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | dirty_writeback_centisecs_handler() cleanupAndrew Morton2007-07-161-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Repair indenting bustage. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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