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2006-03-22[PATCH] mm: page_alloc less atomicsNick Piggin
More atomic operation removal from page allocator Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: less atomic opsNick Piggin
In the page release paths, we can be sure that nobody will mess with our page->flags because the refcount has dropped to 0. So no need for atomic operations here. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: PageActive no testsetNick Piggin
PG_active is protected by zone->lru_lock, it does not need TestSet/TestClear operations. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: PageLRU no testsetNick Piggin
PG_lru is protected by zone->lru_lock. It does not need TestSet/TestClear operations. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] mm: never ClearPageLRU released pagesNick Piggin
If vmscan finds a zero refcount page on the lru list, never ClearPageLRU it. This means the release code need not hold ->lru_lock to stabilise PageLRU, so that lock may be skipped entirely when releasing !PageLRU pages (because we know PageLRU won't have been temporarily cleared by vmscan, which was previously guaranteed by holding the lock to synchronise against vmscan). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] __get_page_state() cpumask cleanup and fixAndrew Morton
__get_page_state() has an open-coded for_each_cpu_mask() loop in it. Tidy that up, then notice that the code was buggy: while (cpu < NR_CPUS) { unsigned long *in, *out, off; if (!cpu_isset(cpu, *cpumask)) continue; an obvious infinite loop. I guess we just never call it with a holey cpu mask. Even after my cpumask size-reduction work, this patch increases code size :( Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] fix free swap cache latencyHugh Dickins
Lee Revell reported 28ms latency when process with lots of swapped memory exits. 2.6.15 introduced a latency regression when unmapping: in accounting the zap_work latency breaker, pte_none counted 1, pte_present PAGE_SIZE, but a swap entry counted nothing at all. We think of pages present as the slow case, but Lee's trace shows that free_swap_and_cache's radix tree lookup can make a lot of work - and we could have been doing it many thousands of times without a latency break. Move the zap_work update up to account swap entries like pages present. This does account non-linear pte_file entries, and unmap_mapping_range skipping over swap entries, by the same amount even though they're quick: but neither of those cases deserves complicating the code (and they're treated no worse than they were in 2.6.14). Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] fix race in pagevec_strip?Christoph Lameter
We can call try_to_release_page() with PagePrivate off and a valid page->mapping This may cause all sorts of trouble for the filesystem *_releasepage() handlers. XFS bombs out in that case. Lock the page before checking for page private. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] page migration: Fail with error if swap not setupChristoph Lameter
Currently the migration of anonymous pages will silently fail if no swap is setup. This patch makes page migration functions check for available swap and fail with -ENODEV if no swap space is available. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-14[PATCH] Consistent capabilites associated with MPOL_MOVE_ALLChristoph Lameter
It seems that setting scheduling policy and priorities is also the kind of thing that might be performed in apps that also use the NUMA API, so it would seem consistent to use CAP_SYS_NICE for NUMA also. So use CAP_SYS_NICE for controlling migration permissions. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-14[PATCH] page migration: fail if page is in a vma flagged VM_LOCKEDChristoph Lameter
page migration currently simply retries a couple of times if try_to_unmap() fails without inspecting the return code. However, SWAP_FAIL indicates that the page is in a vma that has the VM_LOCKED flag set (if ignore_refs ==1). We can check for that return code and avoid retrying the migration. migrate_page_remove_references() now needs to return a reason why the failure occured. So switch migrate_page_remove_references to use -Exx style error messages. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-09[PATCH] slab: Node rotor for freeing alien caches and remote per cpu pages.Christoph Lameter
The cache reaper currently tries to free all alien caches and all remote per cpu pages in each pass of cache_reap. For a machines with large number of nodes (such as Altix) this may lead to sporadic delays of around ~10ms. Interrupts are disabled while reclaiming creating unacceptable delays. This patch changes that behavior by adding a per cpu reap_node variable. Instead of attempting to free all caches, we free only one alien cache and the per cpu pages from one remote node. That reduces the time spend in cache_reap. However, doing so will lengthen the time it takes to completely drain all remote per cpu pagesets and all alien caches. The time needed will grow with the number of nodes in the system. All caches are drained when they overflow their respective capacity. So the drawback here is only that a bit of memory may be wasted for awhile longer. Details: 1. Rename drain_remote_pages to drain_node_pages to allow the specification of the node to drain of pcp pages. 2. Add additional functions init_reap_node, next_reap_node for NUMA that manage a per cpu reap_node counter. 3. Add a reap_alien function that reaps only from the current reap_node. For us this seems to be a critical issue. Holdoffs of an average of ~7ms cause some HPC benchmarks to slow down significantly. F.e. NAS parallel slows down dramatically. NAS parallel has a 12-16 seconds runtime w/o rotor compared to 5.8 secs with the rotor patches. It gets down to 5.05 secs with the additional interrupt holdoff reductions. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-09[PATCH] memory hotadd: pgdat->node_present_pages fixYasunori Goto
When pages are onlined, not only zone->present_pages but also pgdat->node_present_pages should be refreshed. This parameter is used to show information at /sys/device/system/node/nodeX/meminfo via si_meminfo_node(). So, it shows strange value for MemUsed which is calculated (node_present_pages - all zones free pages). Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-09[PATCH] vmscan: no zone_reclaim if PF_MALLOC is setChristoph Lameter
If the process has already set PF_MALLOC and is already using current->reclaim_state then do not try to reclaim memory from the zone. This is set by kswapd and/or synchrononous global reclaim which will not take it lightly if we zap the reclaim_state. Signed-off-by: Christoph Lameter <clameter@sig.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-09[PATCH] page_add_file_rmap(): remove BUG_ON()sHugh Dickins
Remove two early-development BUG_ONs from page_add_file_rmap. The pfn_valid test (originally useful for checking that nobody passed an artificial struct page) comes too late, since we already have the struct page. The PageAnon test (useful when anon was first distinguished from file rmap) prevents ->nopage implementations from reusing ->mapping, which would otherwise be available. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08[PATCH] slab: allocate larger cache_cache if order 0 failsJack Steiner
kmem_cache_init() incorrectly assumes that the cache_cache object will fit in an order 0 allocation. On very large systems, this is not true. Change the code to try larger order allocations if order 0 fails. Signed-off-by: Jack Steiner <steiner@sgi.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08[PATCH] percpu_counter_sum()Andrew Morton
Implement percpu_counter_sum(). This is a more accurate but slower version of percpu_counter_read_positive(). We need this for Alex's speedup-ext3_statfs patch and for the nr_file accounting fix. Otherwise these things would be too inaccurate on large CPU counts. Cc: Ravikiran G Thirumalai <kiran@scalex86.org> Cc: Alex Tomas <alex@clusterfs.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08[PATCH] numa_maps-update fixAndrew Morton
Fix the mm/mempolicy.c build for !CONFIG_HUGETLB_PAGE. Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Martin Bligh <mbligh@google.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08slab: fix calculate_slab_order() for SLAB_RECLAIM_ACCOUNTLinus Torvalds
Instead of having a hard-to-read and confusing conditional in the caller, just make the slab order calculation handle this special case, since it's simple and obvious there. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06[PATCH] numa_maps updateChristoph Lameter
Change the format of numa_maps to be more compact and contain additional information that is useful for managing and troubleshooting memory on a NUMA system. Numa_maps can now also support huge pages. Fixes: 1. More compact format. Only display fields if they contain additional information. 2. Always display information for all vmas. The old numa_maps did not display vma with no mapped entries. This was a bit confusing because page migration removes ptes for file backed vmas. After page migration a part of the vmas vanished. 3. Rename maxref to maxmap. This is the maximum mapcount of all the pages in a vma and may be used as an indicator as to how many processes may be using a certain vma. 4. Include the ability to scan over huge page vmas. New items shown: dirty Number of pages in a vma that have either the dirty bit set in the page_struct or in the pte. file=<filename> The file backing the pages if any stack Stack area heap Heap area huge Huge page area. The number of pages shows is the number of huge pages not the regular sized pages. swapcache Number of pages with swap references. Must be >0 in order to be shown. active Number of active pages. Only displayed if different from the number of pages mapped. writeback Number of pages under writeback. Only displayed if >0. Sample ouput of a process using huge pages: 00000000 default 2000000000000000 default file=/lib/ld-2.3.90.so mapped=13 mapmax=30 N0=13 2000000000044000 default file=/lib/ld-2.3.90.so anon=2 dirty=2 swapcache=2 N2=2 2000000000064000 default file=/lib/librt-2.3.90.so mapped=2 active=1 N1=1 N3=1 2000000000074000 default file=/lib/librt-2.3.90.so 2000000000080000 default file=/lib/librt-2.3.90.so anon=1 swapcache=1 N2=1 2000000000084000 default 2000000000088000 default file=/lib/libc-2.3.90.so mapped=52 mapmax=32 active=48 N0=52 20000000002bc000 default file=/lib/libc-2.3.90.so 20000000002c8000 default file=/lib/libc-2.3.90.so anon=3 dirty=2 swapcache=3 active=2 N1=1 N2=2 20000000002d4000 default anon=1 swapcache=1 N1=1 20000000002d8000 default file=/lib/libpthread-2.3.90.so mapped=8 mapmax=3 active=7 N2=2 N3=6 20000000002fc000 default file=/lib/libpthread-2.3.90.so 2000000000308000 default file=/lib/libpthread-2.3.90.so anon=1 dirty=1 swapcache=1 N1=1 200000000030c000 default anon=1 dirty=1 swapcache=1 N1=1 2000000000320000 default anon=1 dirty=1 N1=1 200000000071c000 default 2000000000720000 default anon=2 dirty=2 swapcache=1 N1=1 N2=1 2000000000f1c000 default 2000000000f20000 default anon=2 dirty=2 swapcache=1 active=1 N2=1 N3=1 200000000171c000 default 2000000001720000 default anon=1 dirty=1 swapcache=1 N1=1 2000000001b20000 default 2000000001b38000 default file=/lib/libgcc_s.so.1 mapped=2 N1=2 2000000001b48000 default file=/lib/libgcc_s.so.1 2000000001b54000 default file=/lib/libgcc_s.so.1 anon=1 dirty=1 active=0 N1=1 2000000001b58000 default file=/lib/libunwind.so.7.0.0 mapped=2 active=1 N1=2 2000000001b74000 default file=/lib/libunwind.so.7.0.0 2000000001b80000 default file=/lib/libunwind.so.7.0.0 2000000001b84000 default 4000000000000000 default file=/media/huge/test9 mapped=1 N1=1 6000000000000000 default file=/media/huge/test9 anon=1 dirty=1 active=0 N1=1 6000000000004000 default heap 607fffff7fffc000 default anon=1 dirty=1 swapcache=1 N2=1 607fffffff06c000 default stack anon=1 dirty=1 active=0 N1=1 8000000060000000 default file=/mnt/huge/test0 huge dirty=3 N1=3 8000000090000000 default file=/mnt/huge/test1 huge dirty=3 N0=1 N2=2 80000000c0000000 default file=/mnt/huge/test2 huge dirty=3 N1=1 N3=2 Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06slab: clarify and fix calculate_slab_order()Linus Torvalds
If we triggered the 'offslab_limit' test, we would return with cachep->gfporder incremented once too many times. This clarifies the logic somewhat, and fixes that bug. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06Fix "check_slabp" printout size calculationLinus Torvalds
We want to use the "struct slab" size, not the size of the pointer to same. As it is, we'd not print out the last <n> entry pointers in the slab (where <n> is ~10, depending on whether it's a 32-bit or 64-bit kernel). Gaah, that slab code was written by somebody who likes unreadable crud. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-02[PATCH] numa_maps: Fix potential crash on non IA64 platformsChristoph Lameter
numa_maps should not scan over huge vmas in order not to cause problems for non IA64 platforms that may have pte entries pointing to huge pages in a variety of ways in their page tables. Add a simple check to ignore vmas containing huge pages. Signed-off-by: Christoph Lameter <clameter@engr.sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-02[PATCH] out_of_memory() locking fixAndrew Morton
I seem to have lost this read_unlock(). While we're there, let's turn that interruptible sleep unto uninterruptible, so we don't get a busywait if signal_pending(). (Again. We seem to have a habit of doing this). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-28[PATCH] out_of_memory(): use of uninitialisedAndrew Morton
Under some circumstances `points' can get printed before it's initialised. Spotted by Carlos Martin <carlos@cmartin.tk>. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-28[PATCH] nommu: implement vmalloc_node()Andrew Morton
Fix oprofile linkage. Pointed out by "Luke Yang" <luke.adi@gmail.com>. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-28[PATCH] remove_from_swap: fix lockingChristoph Lameter
remove_from_swap() currently attempts to use page_lock_anon_vma to obtain an anon_vma lock. That is not working since the page may have been remapped via swap ptes in order to move the page. However, do_migrate_pages() obtain the mmap_sem lock and therefore there is a guarantee that the anonymous vma will not vanish from under us. There is therefore no need to use page_lock_anon_vma. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-28[PATCH] Fix sys_migrate_pages: Move all pages when invoked from rootChristoph Lameter
Currently sys_migrate_pages only moves pages belonging to a process. This is okay when invoked from a regular user. But if invoked from root it should move all pages as documented in the migrate_pages manpage. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24[PATCH] vmscan: fix zone_reclaimChristoph Lameter
- PF_SWAPWRITE needs to be set for RECLAIM_SWAP to be able to write out pages to swap. Currently RECLAIM_SWAP may not do that. - remove setting nr_reclaimed pages after slab reclaim since the slab shrinking code does not use that and the nr_reclaimed pages is just right for the intended follow up action. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24[PATCH] page migration: Fix MPOL_INTERLEAVE behavior for migration via mbind()Christoph Lameter
migrate_pages_to() allocates a list of new pages on the intended target node or with the intended policy and then uses the list of new pages as targets for the migration of a list of pages out of place. When the pages are allocated it is not clear which of the out of place pages will be moved to the new pages. So we cannot specify an address as needed by alloc_page_vma(). This causes problem for MPOL_INTERLEAVE which will currently allocate the pages on the first node of the set. If mbind is used with vma that has the policy of MPOL_INTERLEAVE then the interleaving of pages may be destroyed. This patch fixes that by generating a fake address for each alloc_page_vma which will result is a distribution of pages as prescribed by MPOL_INTERLEAVE. Lee also noted that the sequence of nodes for the new pages seems to be inverted. So we also invert the way the lists of pages for migration are build. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Looks-ok-to: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-21[PATCH] tmpfs: fix mount mpol nodelist parsingHugh Dickins
I've been dissatisfied with the mpol_nodelist mount option which was added to tmpfs earlier in -rc. Replace it by mpol=policy:nodelist. And it was broken: a nodelist is a comma-separated list of numbers and ranges; the mount options are a comma-separated list of token=values. Whoops, blindly strsep'ing on commas doesn't work so well: since we've no numeric tokens, and unlikely to add them, use that to distinguish. Move the mpol= parsing to shmem_parse_mpol under CONFIG_NUMA, reject all its options as invalid if not NUMA. /proc shows MPOL_PREFERRED as "prefer", so use that name for the policy instead of "preferred". Enforce that mpol=default has no nodelist; that mpol=prefer has one node only; that mpol=bind has a nodelist; but let mpol=interleave use node_online_map if no nodelist given. Describe this in tmpfs.txt. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Robin Holt <holt@sgi.com> Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20[PATCH] mm/mempolicy.c: fix 'if ();' typoAlexey Dobriyan
[akpm; it happens that the code was still correct, only inefficient ] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christoph Lameter <christoph@lameter.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20[PATCH] Fix undefined symbols for nommu architectureLuke Yang
Signed-off-by: Luke Yang <luke.adi@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20[PATCH] Fix units in mbind checkAndi Kleen
maxnode is a bit index and can't be directly compared against a byte length like PAGE_SIZE Signed-off-by: Andi Kleen <ak@suse.de> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20[PATCH] Terminate process that fails on a constrained allocationChristoph Lameter
Some allocations are restricted to a limited set of nodes (due to memory policies or cpuset constraints). If the page allocator is not able to find enough memory then that does not mean that overall system memory is low. In particular going postal and more or less randomly shooting at processes is not likely going to help the situation but may just lead to suicide (the whole system coming down). It is better to signal to the process that no memory exists given the constraints that the process (or the configuration of the process) has placed on the allocation behavior. The process may be killed but then the sysadmin or developer can investigate the situation. The solution is similar to what we do when running out of hugepages. This patch adds a check before we kill processes. At that point performance considerations do not matter much so we just scan the zonelist and reconstruct a list of nodes. If the list of nodes does not contain all online nodes then this is a constrained allocation and we should kill the current process. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20[PATCH] OOM kill: children accountingKurt Garloff
In the badness() calculation, there's currently this piece of code: /* * Processes which fork a lot of child processes are likely * a good choice. We add the vmsize of the children if they * have an own mm. This prevents forking servers to flood the * machine with an endless amount of children */ list_for_each(tsk, &p->children) { struct task_struct *chld; chld = list_entry(tsk, struct task_struct, sibling); if (chld->mm = p->mm && chld->mm) points += chld->mm->total_vm; } The intention is clear: If some server (apache) keeps spawning new children and we run OOM, we want to kill the father rather than picking a child. This -- to some degree -- also helps a bit with getting fork bombs under control, though I'd consider this a desirable side-effect rather than a feature. There's one problem with this: No matter how many or few children there are, if just one of them misbehaves, and all others (including the father) do everything right, we still always kill the whole family. This hits in real life; whether it's javascript in konqueror resulting in kdeinit (and thus the whole KDE session) being hit or just a classical server that spawns children. Sidenote: The killer does kill all direct children as well, not only the selected father, see oom_kill_process(). The idea in attached patch is that we do want to account the memory consumption of the (direct) children to the father -- however not fully. This maintains the property that fathers with too many children will still very likely be picked, whereas a single misbehaving child has the chance to be picked by the OOM killer. In the patch I account only half (rounded up) of the children's vm_size to the parent. This means that if one child eats more mem than the rest of the family, it will be picked, otherwise it's still the father and thus the whole family that gets selected. This is heuristics -- we could debate whether accounting for a fourth would be better than for half of it. Or -- if people would consider it worth the trouble -- make it a sysctl. For now I sticked to accounting for half, which should IMHO be a significant improvement. The patch does one more thing: As users tend to be irritated by the choice of killed processes (mainly because the children are killed first, despite some of them having a very low OOM score), I added some more output: The selected (father) process will be reported first and it's oom_score printed to syslog. Description: Only account for half of children's vm size in oom score calculation This should still give the parent enough point in case of fork bombs. If any child however has more than 50% of the vm size of all children together, it'll get a higher score and be elected. This patch also makes the kernel display the oom_score. Signed-off-by: Kurt Garloff <garloff@suse.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17[PATCH] sys_mbind sanity checkingChris Wright
Make sure maxnodes is safe size before calculating nlongs in get_nodes(). Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17[PATCH] Handle holes in node mask in node fallback list setupLinus Torvalds
Change the find_next_best_node algorithm to correctly skip over holes in the node online mask. Previously it would not handle missing nodes correctly and cause crashes at boot. [Written by Linus, tested by AK] Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17[PATCH] Handle all and empty zones when setting up custom zonelists for mbindAndi Kleen
The memory allocator doesn't like empty zones (which have an uninitialized freelist), so a x86-64 system with a node fully in GFP_DMA32 only would crash on mbind. Fix that up by putting all possible zones as fallback into the zonelist and skipping the empty ones. In fact the code always enough allocated space for all zones, but only used it for the highest. This change just uses all the memory that was allocated before. This should work fine for now, but whoever implements node hot removal needs to fix this somewhere else too (or make sure zone datastructures by itself never go away, only their memory) Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17[PATCH] x86_64: Add boot option to disable randomized mappings and cleanupAndi Kleen
AMD SimNow!'s JIT doesn't like them at all in the guest. For distribution installation it's easiest if it's a boot time option. Also I moved the variable to a more appropiate place and make it independent from sysctl And marked __read_mostly which it is. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14[PATCH] madvise MADV_DONTFORK/MADV_DOFORKMichael S. Tsirkin
Currently, copy-on-write may change the physical address of a page even if the user requested that the page is pinned in memory (either by mlock or by get_user_pages). This happens if the process forks meanwhile, and the parent writes to that page. As a result, the page is orphaned: in case of get_user_pages, the application will never see any data hardware DMA's into this page after the COW. In case of mlock'd memory, the parent is not getting the realtime/security benefits of mlock. In particular, this affects the Infiniband modules which do DMA from and into user pages all the time. This patch adds madvise options to control whether memory range is inherited across fork. Useful e.g. for when hardware is doing DMA from/into these pages. Could also be useful to an application wanting to speed up its forks by cutting large areas out of consideration. Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14[PATCH] compound page: default destructorHugh Dickins
Somehow I imagined that calling a NULL destructor would free a compound page rather than oopsing. No, we must supply a default destructor, __free_pages_ok using the order noted by prep_compound_page. hugetlb can still replace this as before with its own free_huge_page pointer. The case that needs this is not common: rarely does put_compound_page's put_page_testzero bring the count down to 0. But if get_user_pages is applied to some part of a compound page, without immediate release (e.g. AIO or Infiniband), then it's possible for its put_page to come after the containing vma has been unmapped and the driver done its free_pages. That's just the kind of case compound pages are supposed to be guarding against (but Nick points out, nor did PageReserved handle this right). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14[PATCH] compound page: use page[1].lruHugh Dickins
If a compound page has its own put_page_testzero destructor (the only current example is free_huge_page), that is noted in page[1].mapping of the compound page. But that's rather a poor place to keep it: functions which call set_page_dirty_lock after get_user_pages (e.g. Infiniband's __ib_umem_release) ought to be checking first, otherwise set_page_dirty is liable to crash on what's not the address of a struct address_space. And now I'm about to make that worse: it turns out that every compound page needs a destructor, so we can no longer rely on hugetlb pages going their own special way, to avoid further problems of page->mapping reuse. For example, not many people know that: on 50% of i386 -Os builds, the first tail page of a compound page purports to be PageAnon (when its destructor has an odd address), which surprises page_add_file_rmap. Keep the compound page destructor in page[1].lru.next instead. And to free up the common pairing of mapping and index, also move compound page order from index to lru.prev. Slab reuses page->lru too: but if we ever need slab to use compound pages, it can easily stack its use above this. (akpm: decoded version of the above: the tail pages of a compound page now have ->mapping==NULL, so there's no need for the set_page_dirty[_lock]() caller to check that they're not compund pages before doing the dirty). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11[PATCH] vmscan: skip reclaim_mapped determination if we do not swapChristoph Lameter
This puts the variables and the way to get to reclaim_mapped in one block. And allows zone_reclaim or other things to skip the determination (maybe this whole block of code does not belong into refill_inactive_zone()?) Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11[PATCH] vmscan: remove duplicate increment of reclaim_in_progressChristoph Lameter
shrink_zone() already increments reclaim_in_progress. No need to do it in balance_pgdat. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11[PATCH] zone reclaim: do not check references to a page during zone reclaimChristoph Lameter
shrink_list() and refill_inactive() check all ptes pointing to a page for reference bits in order to decide if the page should be put on the active list. This is not necessary for zone_reclaim since we are only interested in removing unmapped pages. Skip the checks in both functions. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-10[PATCH] Updates for page migrationChristoph Lameter
This adds some additional comments in order to help others figure out how exactly the code works. And fix a variable name. Also swap_page does need to ignore all reference bits when unmapping a page. Otherwise we may have to repeatedly unmap a frequently touched page. So change the try_to_unmap parameter to 1. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-10[PATCH] slab: Avoid deadlock at kmem_cache_create/kmem_cache_destroyRavikiran G Thirumalai
Prevents deadlock situation between kmem_cache_create()/kmem_cache_destory(), and kmem_cache_create() /cpu hotplug. The locking order probably got moved over time. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-08[PATCH] SLOB=y && SMP=y fixIngo Molnar
fix CONFIG_SLOB=y (when CONFIG_SMP=y): get rid of the 'align' parameter from its __alloc_percpu() implementation. Boot-tested on x86. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07[PATCH] mm: compound release fixNick Piggin
Compound pages on SMP systems can now often be freed from pagetables via the release_pages path. This uses put_page_testzero which does not handle compound pages at all. Releasing constituent pages from process mappings decrements their count to a large negative number and leaks the reference at the head page - net result is a memory leak. The problem was hidden because the debug check in put_page_testzero itself actually did take compound pages into consideration. Fix the bug and the debug check. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>