- 14 Sep, 2009 1 commit
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Frederic Weisbecker authored
This patch is an attempt to remove the Bkl based locking scheme from reiserfs and is intended. It is a bit inspired from an old attempt by Peter Zijlstra: http://lkml.indiana.edu/hypermail/linux/kernel/0704.2/2174.html The bkl is heavily used in this filesystem to prevent from concurrent write accesses on the filesystem. Reiserfs makes a deep use of the specific properties of the Bkl: - It can be acqquired recursively by a same task - It is released on the schedule() calls and reacquired when schedule() returns The two properties above are a roadmap for the reiserfs write locking so it's very hard to simply replace it with a common mutex. - We need a recursive-able locking unless we want to restructure several blocks of the code. - We need to identify the sites where the bkl was implictly relaxed (schedule, wait, sync, etc...) so that we can in turn release and reacquire our new lock explicitly. Such implicit releases of the lock are often required to let other resources producer/consumer do their job or we can suffer unexpected starvations or deadlocks. So the new lock that replaces the bkl here is a per superblock mutex with a specific property: it can be acquired recursively by a same task, like the bkl. For such purpose, we integrate a lock owner and a lock depth field on the superblock information structure. The first axis on this patch is to turn reiserfs_write_(un)lock() function into a wrapper to manage this mutex. Also some explicit calls to lock_kernel() have been converted to reiserfs_write_lock() helpers. The second axis is to find the important blocking sites (schedule...(), wait_on_buffer(), sync_dirty_buffer(), etc...) and then apply an explicit release of the write lock on these locations before blocking. Then we can safely wait for those who can give us resources or those who need some. Typically this is a fight between the current writer, the reiserfs workqueue (aka the async commiter) and the pdflush threads. The third axis is a consequence of the second. The write lock is usually on top of a lock dependency chain which can include the journal lock, the flush lock or the commit lock. So it's dangerous to release and trying to reacquire the write lock while we still hold other locks. This is fine with the bkl: T1 T2 lock_kernel() mutex_lock(A) unlock_kernel() // do something lock_kernel() mutex_lock(A) -> already locked by T1 schedule() (and then unlock_kernel()) lock_kernel() mutex_unlock(A) .... This is not fine with a mutex: T1 T2 mutex_lock(write) mutex_lock(A) mutex_unlock(write) // do something mutex_lock(write) mutex_lock(A) -> already locked by T1 schedule() mutex_lock(write) -> already locked by T2 deadlock The solution in this patch is to provide a helper which releases the write lock and sleep a bit if we can't lock a mutex that depend on it. It's another simulation of the bkl behaviour. The last axis is to locate the fs callbacks that are called with the bkl held, according to Documentation/filesystem/Locking. Those are: - reiserfs_remount - reiserfs_fill_super - reiserfs_put_super Reiserfs didn't need to explicitly lock because of the context of these callbacks. But now we must take care of that with the new locking. After this patch, reiserfs suffers from a slight performance regression (for now). On UP, a high volume write with dd reports an average of 27 MB/s instead of 30 MB/s without the patch applied. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Bron Gondwana <brong@fastmail.fm> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> LKML-Reference: <1239070789-13354-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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- 09 Sep, 2009 3 commits
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Linus Torvalds authored
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Ed Cashin authored
Andy Whitcroft reported an oops in aoe triggered by use of an incorrectly initialised request_queue object: [ 2645.959090] kobject '<NULL>' (ffff880059ca22c0): tried to add an uninitialized object, something is seriously wrong. [ 2645.959104] Pid: 6, comm: events/0 Not tainted 2.6.31-5-generic #24-Ubuntu [ 2645.959107] Call Trace: [ 2645.959139] [<ffffffff8126ca2f>] kobject_add+0x5f/0x70 [ 2645.959151] [<ffffffff8125b4ab>] blk_register_queue+0x8b/0xf0 [ 2645.959155] [<ffffffff8126043f>] add_disk+0x8f/0x160 [ 2645.959161] [<ffffffffa01673c4>] aoeblk_gdalloc+0x164/0x1c0 [aoe] The request queue of an aoe device is not used but can be allocated in code that does not sleep. Bruno bisected this regression down to cd43e26f block: Expose stacked device queues in sysfs "This seems to generate /sys/block/$device/queue and its contents for everyone who is using queues, not just for those queues that have a non-NULL queue->request_fn." Addresses http://bugs.launchpad.net/bugs/410198 Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13942 Note that embedding a queue inside another object has always been an illegal construct, since the queues are reference counted and must persist until the last reference is dropped. So aoe was always buggy in this respect (Jens). Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Bruno Premont <bonbons@linux-vserver.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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Linus Torvalds authored
Reinette Chatre reports a frozen system (with blinking keyboard LEDs) when switching from graphics mode to the text console, or when suspending (which does the same thing). With netconsole, the oops turned out to be BUG: unable to handle kernel NULL pointer dereference at 0000000000000084 IP: [<ffffffffa03ecaab>] i915_driver_irq_handler+0x26b/0xd20 [i915] and it's due to the i915_gem.c code doing drm_irq_uninstall() after having done i915_gem_idle(). And the i915_gem_idle() path will do i915_gem_idle() -> i915_gem_cleanup_ringbuffer() -> i915_gem_cleanup_hws() -> dev_priv->hw_status_page = NULL; but if an i915 interrupt comes in after this stage, it may want to access that hw_status_page, and gets the above NULL pointer dereference. And since the NULL pointer dereference happens from within an interrupt, and with the screen still in graphics mode, the common end result is simply a silently hung machine. Fix it by simply uninstalling the irq handler before idling rather than after. Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13819Reported-and-tested-by: Reinette Chatre <reinette.chatre@intel.com> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- 08 Sep, 2009 1 commit
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Zhenyu Wang authored
eDP is exclusive connector too, and add missing crtc_mask setting for TV. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=14139Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> Reported-and-tested-by: Carlos R. Mafra <crmafra2@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- 07 Sep, 2009 7 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6Linus Torvalds authored
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: drm/radeon/kms: add LTE/GTE discard + rv515 two sided stencil register.
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Linus Torvalds authored
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: IMA: update ima_counts_put
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: gianfar: Fix build.
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6Linus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6: pcmcia: add CNF-CDROM-ID for ide
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git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intelLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: agp/intel: support for new chip variant of IGDNG mobile drm/i915: Unref old_obj on get_fence_reg() error path drm/i915: increase default latency constant (v2 w/comment)
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Dave Airlie authored
This adds some rv350+ register for LTE/GTE discard, and enables the rv515 two sided stencil register. It also disables the DEPTHXY_OFFSET register which can be used to workaround the CS checker. Moves rs690 to proper place in rs600 and uses correct table on rs600. Signed-off-by: Dave Airlie <airlied@redhat.com>
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Mimi Zohar authored
- As ima_counts_put() may be called after the inode has been freed, verify that the inode is not NULL, before dereferencing it. - Maintain the IMA file counters in may_open() properly, decrementing any counter increments on subsequent errors. Reported-by: Ciprian Docan <docan@eden.rutgers.edu> Reported-by: J.R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com Signed-off-by: James Morris <jmorris@namei.org>
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- 06 Sep, 2009 1 commit
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David S. Miller authored
Reported by Michael Guntsche <mike@it-loops.com> -------------------- Commit 38bddf04 gianfar: gfar_remove needs to call unregister_netdev() breaks the build of the gianfar driver because "dev" is undefined in this function. To quickly test rc9 I changed this to priv->ndev but I do not know if this is the correct one. -------------------- Signed-off-by: David S. Miller <davem@davemloft.net>
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- 05 Sep, 2009 27 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6Linus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: sbp2: fix freeing of unallocated memory firewire: ohci: fix Ricoh R5C832, video reception firewire: ohci: fix Agere FW643 and multiple cameras firewire: core: fix crash in iso resource management
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Roderick Colenbrander authored
This patch fixes a null pointer exception caused by removal of 'ack()' for level interrupts in the Xilinx interrupt driver. A recent change to the xilinx interrupt controller removed the ack hook for level irqs. Signed-off-by: Roderick Colenbrander <thunderbird2k@gmail.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.infradead.org/~dwmw2/mtd-2.6.31Linus Torvalds authored
* git://git.infradead.org/~dwmw2/mtd-2.6.31: JFFS2: add missing verify buffer allocation/deallocation mtd: nftl: fix offset alignments mtd: nftl: write support is broken mtd: m25p80: fix null pointer dereference bug
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git://git.kernel.dk/linux-2.6-blockLinus Torvalds authored
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: Allow changing max_sectors_kb above the default 512
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6Linus Torvalds authored
* 'fix/oxygen' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: sound: oxygen: handle cards with missing EEPROM sound: oxygen: fix MCLK rate for 192 kHz playback
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: tc: Fix unitialized kernel memory leak pkt_sched: Revert tasklet_hrtimer changes. net: sk_free() should be allowed right after sk_alloc() gianfar: gfar_remove needs to call unregister_netdev() ipw2200: firmware DMA loading rework
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: skcipher - Fix skcipher_dequeue_givcrypt NULL test
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git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreqLinus Torvalds authored
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Re-enable cpufreq suspend and resume code
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git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6Linus Torvalds authored
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] fix csum_ipv6_magic() [IA64] Fix warning in dma-mapping.c
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git://oss.sgi.com/xfs/xfsLinus Torvalds authored
* 'for-linus' of git://oss.sgi.com/xfs/xfs: xfs: actually enable the swapext compat handler
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git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2Linus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: nilfs2: fix preempt count underflow in nilfs_btnode_prepare_change_key
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpuLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: don't assume existence of cpu0
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git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6Linus Torvalds authored
* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU
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git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: dm snapshot: fix on disk chunk size validation dm exception store: split set_chunk_size dm snapshot: fix header corruption race on invalidation dm snapshot: refactor zero_disk_area to use chunk_io dm log: userspace add luid to distinguish between concurrent log instances dm raid1: do not allow log_failure variable to unset after being set dm log: remove incorrect field from userspace table output dm log: fix userspace status output dm stripe: expose correct io hints dm table: add more context to terse warning messages dm table: fix queue_limit checking device iterator dm snapshot: implement iterate devices dm multipath: fix oops when request based io fails when no paths
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git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6Linus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: PCI SR-IOV: correct broken resource alignment calculations
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc64: Fix bootup with mcount in some configs. sparc64: Kill spurious NMI watchdog triggers by increasing limit to 30 seconds.
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Linus Torvalds authored
Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter/powerpc: Fix cache event codes for POWER7 perf_counter: Fix /0 bug in swcounters perf_counters: Increase paranoia level
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git://git.kernel.org/pub/scm/linux/kernel/git/dtor/inputLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: atkbd - add Compaq Presario R4000-series repeat quirk Input: i8042 - add Acer Aspire 5536 to the nomux list
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Nicolas Pitre authored
In ext2_rename(), dir_page is acquired through ext2_dotdot(). It is then released through ext2_set_link() but only if old_dir != new_dir. Failing that, the pkmap reference count is never decremented and the page remains pinned forever. Repeat that a couple times with highmem pages and all pkmap slots get exhausted, and every further kmap() calls end up stalling on the pkmap_map_wait queue at which point the whole system comes to a halt. Signed-off-by: Nicolas Pitre <nico@marvell.com> Acked-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2Linus Torvalds authored
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: ocfs2: ocfs2_write_begin_nolock() should handle len=0 ocfs2: invalidate dentry if its dentry_lock isn't initialized.
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Linus Torvalds authored
The whole write-room thing is something that is up to the _caller_ to worry about, not the pty layer itself. The total buffer space will still be limited by the buffering routines themselves, so there is no advantage or need in having pty_write() artificially limit the size somehow. And what happened was that the caller (the n_tty line discipline, in this case) may have verified that there is room for 2 bytes to be written (for NL -> CRNL expansion), and it used to then do those writes as two single-byte writes. And if the first byte written (CR) then caused a new tty buffer to be allocated, pty_space() may have returned zero when trying to write the second byte (LF), and then incorrectly failed the write - leading to a lost newline character. This should finally fix http://bugzilla.kernel.org/show_bug.cgi?id=14015Reported-by: Mikael Pettersson <mikpe@it.uu.se> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
When translating CR to CRNL in the n_tty line discipline, we did it as two tty_put_char() calls. Which works, but is stupid, and has caused problems before too with bad interactions with the write_room() logic. The generic USB serial driver had that problem, for example. Now the pty layer had similar issues after being moved to the generic tty buffering code (in commit d945cb9c: "pty: Rework the pty layer to use the normal buffering logic"). So stop doing the silly separate two writes, and do it as a single write instead. That's what the n_tty layer already does for the space expansion of tabs (XTABS), and it means that we'll now always have just a single write for the CRNL to match the single 'tty_write_room()' test, which hopefully means that the next time somebody screws up buffering, it won't cause weeks of debugging. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Oleg Nesterov authored
Tom Horsley reports that his debugger hangs when it tries to read /proc/pid_of_tracee/maps, this happens since "mm_for_maps: take ->cred_guard_mutex to fix the race with exec" 04b836cbf19e885f8366bccb2e4b0474346c02d commit in 2.6.31. But the root of the problem lies in the fact that do_execve() path calls tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC. The tracee must not sleep in TASK_TRACED holding this mutex. Even if we remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(), another task doing PTRACE_ATTACH should not hang until it is killed or the tracee resumes. With this patch do_execve() does not use ->cred_guard_mutex directly and we do not hold it throughout, instead: - introduce prepare_bprm_creds() helper, it locks the mutex and calls prepare_exec_creds() to initialize bprm->cred. - install_exec_creds() drops the mutex after commit_creds(), and thus before tracehook_report_exec()->ptrace_stop(). or, if exec fails, free_bprm() drops this mutex when bprm->cred != NULL which indicates install_exec_creds() was not called. Reported-by: Tom Horsley <tom.horsley@att.net> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mel Gorman authored
On low-memory systems, anti-fragmentation gets disabled as fragmentation cannot be avoided on a sufficiently large boundary to be worthwhile. Once disabled, there is a period of time when all the pageblocks are marked MOVABLE and the expectation is that they get marked UNMOVABLE at each call to __rmqueue_fallback(). However, when MAX_ORDER is large the pageblocks do not change ownership because the normal criteria are not met. This has the effect of prematurely breaking up too many large contiguous blocks. This is most serious on NOMMU systems which depend on high-order allocations to boot. This patch causes pageblocks to change ownership on every fallback when anti-fragmentation is disabled. This prevents the large blocks being prematurely broken up. This is a fix to commit 49255c61 [page allocator: move check for disabled anti-fragmentation out of fastpath] and the problem affects 2.6.31-rc8. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Paul Mundt <lethal@linux-sh.org> Cc: David Howells <dhowells@redhat.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Howells authored
Fix the error handling in do_mmap_pgoff(). If do_mmap_shared_file() or do_mmap_private() fail, we jump to the error_put_region label at which point we cann __put_nommu_region() on the region - but we haven't yet added the region to the tree, and so __put_nommu_region() may BUG because the region tree is empty or it may corrupt the region tree. To get around this, we can afford to add the region to the region tree before calling do_mmap_shared_file() or do_mmap_private() as we keep nommu_region_sem write-locked, so no-one can race with us by seeing a transient region. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Mel Gorman <mel@csn.ul.ie> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Oleg Nesterov authored
cancel_delayed_work() has to use del_timer_sync() to guarantee the timer function is not running after return. But most users doesn't actually need this, and del_timer_sync() has problems: it is not useable from interrupt, and it depends on every lock which could be taken from irq. Introduce __cancel_delayed_work() which calls del_timer() instead. The immediate reason for this patch is http://bugzilla.kernel.org/show_bug.cgi?id=13757 but hopefully this helper makes sense anyway. As for 13757 bug, actually we need requeue_delayed_work(), but its semantics are not yet clear. Merge this patch early to resolves cross-tree interdependencies between input and infiniband. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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