- 09 Aug, 2012 27 commits
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Brian Foster authored
commit 97795d2a upstream. If we hit a condition where we have allocated metadata blocks that were not appropriately reserved, we risk underflow of ei->i_reserved_meta_blocks. In turn, this can throw sbi->s_dirtyclusters_counter significantly out of whack and undermine the nondelalloc fallback logic in ext4_nonda_switch(). Warn if this occurs and set i_allocated_meta_blocks to avoid this problem. This condition is reproduced by xfstests 270 against ext2 with delalloc enabled: Mar 28 08:58:02 localhost kernel: [ 171.526344] EXT4-fs (loop1): delayed block allocation failed for inode 14 at logical offset 64486 with max blocks 64 with error -28 Mar 28 08:58:02 localhost kernel: [ 171.526346] EXT4-fs (loop1): This should not happen!! Data will be lost 270 ultimately fails with an inconsistent filesystem and requires an fsck to repair. The cause of the error is an underflow in ext4_da_update_reserve_space() due to an unreserved meta block allocation. Signed-off-by:
Brian Foster <bfoster@redhat.com> Signed-off-by:
"Theodore Ts'o" <tytso@mit.edu> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Theodore Ts'o authored
commit f6fb99ca upstream. Make it possible for ext4_count_free to operate on buffers and not just data in buffer_heads. Signed-off-by:
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Jeff Layton authored
commit 5cf02d09 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 #24 [ffff8810343bfee8] kthread at ffffffff8108dd96 #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by:
Jeff Layton <jlayton@redhat.com> Signed-off-by:
Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by:
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J. Bruce Fields authored
commit 2930d381 upstream. Actually, xfs and jfs can optionally be case insensitive; we'll handle that case in later patches. Signed-off-by:
J. Bruce Fields <bfields@redhat.com> Signed-off-by:
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Jerome Glisse authored
commit ca2ccde5 upstream. To have DP behave like VGA/DVI we need to retrain the link on hotplug. For this to happen we need to force link training to happen by setting connector dpms to off before asking it turning it on again. v2: agd5f - drop the dp_get_link_status() change in atombios_dp.c for now. We still need the dpms OFF change. Signed-off-by:
Jerome Glisse <jglisse@redhat.com> Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
Dave Airlie <airlied@redhat.com> Signed-off-by:
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Jerome Glisse authored
commit 266dcba5 upstream. No need to retrain the link for passive adapters. v2: agd5f - no passive DP to VGA adapters, update comments - assign radeon_connector_atom_dig after we are sure we have a digital connector as analog connectors have different private data. - get new sink type before checking for retrain. No need to check if it's no longer a DP connection. Signed-off-by:
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Jerome Glisse authored
commit 8d1c702a upstream. We want to print link status query failed only if it's an unexepected fail. If we query to see if we need link training it might be because there is nothing connected and thus link status query have the right to fail in that case. To avoid printing failure when it's expected, move the failure message to proper place. Signed-off-by:
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Michel Dänzer authored
commit f60ec4c7 upstream. This could previously fail if either of the enabled displays was using a horizontal resolution that is a multiple of 128, and only the leftmost column of the cursor was (supposed to be) visible at the right edge of that display. The solution is to move the cursor one pixel to the left in that case. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33183Signed-off-by:
Michel Dänzer <michel.daenzer@amd.com> Reviewed-by:
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Chris Mason authored
commit e9fbcb42 upstream. Each ordered operation has a free callback, and this was called with the worker spinlock held. Josef made the free callback also call iput, which we can't do with the spinlock. This drops the spinlock for the free operation and grabs it again before moving through the rest of the list. We'll circle back around to this and find a cleaner way that doesn't bounce the lock around so much. Signed-off-by:
Chris Mason <chris.mason@fusionio.com> Signed-off-by:
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Lan Tianyu authored
commit f197ac13 upstream. In the ac.c, power_supply_register()'s return value is not checked. As a result, the driver's add() ops may return success even though the device failed to initialize. For example, some BIOS may describe two ACADs in the same DSDT. The second ACAD device will fail to register, but ACPI driver's add() ops returns sucessfully. The ACPI device will receive ACPI notification and cause OOPS. https://bugzilla.redhat.com/show_bug.cgi?id=772730Signed-off-by:
Lan Tianyu <tianyu.lan@intel.com> Signed-off-by:
Len Brown <len.brown@intel.com> Signed-off-by:
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Tejun Heo authored
commit 65758202 upstream. Currently, all workqueue cpu hotplug operations run off CPU_PRI_WORKQUEUE which is higher than normal notifiers. This is to ensure that workqueue is up and running while bringing up a CPU before other notifiers try to use workqueue on the CPU. Per-cpu workqueues are supposed to remain working and bound to the CPU for normal CPU_DOWN_PREPARE notifiers. This holds mostly true even with workqueue offlining running with higher priority because workqueue CPU_DOWN_PREPARE only creates a bound trustee thread which runs the per-cpu workqueue without concurrency management without explicitly detaching the existing workers. However, if the trustee needs to create new workers, it creates unbound workers which may wander off to other CPUs while CPU_DOWN_PREPARE notifiers are in progress. Furthermore, if the CPU down is cancelled, the per-CPU workqueue may end up with workers which aren't bound to the CPU. While reliably reproducible with a convoluted artificial test-case involving scheduling and flushing CPU burning work items from CPU down notifiers, this isn't very likely to happen in the wild, and, even when it happens, the effects are likely to be hidden by the following successful CPU down. Fix it by using different priorities for up and down notifiers - high priority for up operations and low priority for down operations. Workqueue cpu hotplug operations will soon go through further cleanup. Signed-off-by:
Tejun Heo <tj@kernel.org> Acked-by:
"Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by:
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Paul Gortmaker authored
commit 2584f521 upstream. Also add information on where the respective trees are. Signed-off-by:
Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by:
Rob Landley <rob@landley.net> Signed-off-by:
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Srivatsa S. Bhat authored
commit 443772d4 upstream. If function tracing is enabled for some of the low-level suspend/resume functions, it leads to triple fault during resume from suspend, ultimately ending up in a reboot instead of a resume (or a total refusal to come out of suspended state, on some machines). This issue was explained in more detail in commit f42ac38c (ftrace: disable tracing for suspend to ram). However, the changes made by that commit got reverted by commit cbe2f5a6 (tracing: allow tracing of suspend/resume & hibernation code again). So, unfortunately since things are not yet robust enough to allow tracing of low-level suspend/resume functions, suspend/resume is still broken when ftrace is enabled. So fix this by disabling function tracing during suspend/resume & hibernation. Signed-off-by:
Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by:
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J. Bruce Fields authored
commit 0ec4f431 upstream. The only checks of the long argument passed to fcntl(fd,F_SETLEASE,.) are done after converting the long to an int. Thus some illegal values may be let through and cause problems in later code. [ They actually *don't* cause problems in mainline, as of Dave Jones's commit 8d657eb3 "Remove easily user-triggerable BUG from generic_setlease", but we should fix this anyway. And this patch will be necessary to fix real bugs on earlier kernels. ] Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Kevin Cernekee authored
commit 31bde1ce upstream. A "usb0" interface that has never been connected to a host has an unknown operstate, and therefore the IFF_RUNNING flag is (incorrectly) asserted when queried by ifconfig, ifplugd, etc. This is a result of calling netif_carrier_off() too early in the probe function; it should be called after register_netdev(). Similar problems have been fixed in many other drivers, e.g.: e826eafa (bonding: Call netif_carrier_off after register_netdevice) 0d672e9f (drivers/net: Call netif_carrier_off at the end of the probe) 6a3c869a (cxgb4: fix reported state of interfaces without link) Fix is to move netif_carrier_off() to the end of the function. Signed-off-by:
Kevin Cernekee <cernekee@gmail.com> Signed-off-by:
Felipe Balbi <balbi@ti.com> Signed-off-by:
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Hans de Goede authored
commit 2102e06a upstream. iso data buffers may have holes in them if some packets were short, so for iso urbs we should always copy the entire buffer, just like the regular processcompl does. Signed-off-by:
Hans de Goede <hdegoede@redhat.com> Acked-by:
Alan Stern <stern@rowland.harvard.edu> Signed-off-by:
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David Henningsson authored
commit 4e01ec63 upstream. This codec has a separate dmic path (separate dmic only ADC), and thus it looks mostly like ALC275. BugLink: https://bugs.launchpad.net/bugs/1025377Tested-by:
Ray Chen <ray.chen@canonical.com> Signed-off-by:
David Henningsson <david.henningsson@canonical.com> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Nishanth Menon authored
commit b110547e upstream. Commit 9fa2df6b (ARM: OMAP2+: OPP: allow OPP enumeration to continue if device is not present) makes the logic: for (i = 0; i < opp_def_size; i++) { <snip> if (!oh || !oh->od) { <snip> continue; } <snip> opp_def++; } In short, the moment we hit a "Bad OPP", we end up looping the list comparing against the bad opp definition pointer for the rest of the iteration count. Instead, increment opp_def in the for loop itself and allow continue to be used in code without much thought so that we check the next set of OPP definition pointers :) Cc: Steve Sakoman <steve@sakoman.com> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by:
Nishanth Menon <nm@ti.com> Signed-off-by:
Kevin Hilman <khilman@ti.com> Signed-off-by:
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Bart Van Assche authored
commit 940f5d47 upstream. When we call scsi_unprep_request() the command associated with the request gets destroyed and therefore drops its reference on the device. If this was the only reference, the device may get released and we end up with a NULL pointer deref when we call blk_requeue_request. Reported-by:
Mike Christie <michaelc@cs.wisc.edu> Signed-off-by:
Bart Van Assche <bvanassche@acm.org> Reviewed-by:
James Bottomley <JBottomley@Parallels.com> Signed-off-by:
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Dan Williams authored
commit 3b661a92 upstream. The following crash results from cases where the end_device has been removed before scsi_sysfs_add_sdev has had a chance to run. BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 IP: [<ffffffff8115e100>] sysfs_create_dir+0x32/0xb6 ... Call Trace: [<ffffffff8125e4a8>] kobject_add_internal+0x120/0x1e3 [<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf [<ffffffff8125e641>] kobject_add_varg+0x41/0x50 [<ffffffff8125e70b>] kobject_add+0x64/0x66 [<ffffffff8131122b>] device_add+0x12d/0x63a [<ffffffff814b65ea>] ? _raw_spin_unlock_irqrestore+0x47/0x56 [<ffffffff8107de15>] ? module_refcount+0x89/0xa0 [<ffffffff8132f348>] scsi_sysfs_add_sdev+0x4e/0x28a [<ffffffff8132dcbb>] do_scan_async+0x9c/0x145 ...teach scsi_sysfs_add_devices() to check for deleted devices() before trying to add them, and teach scsi_remove_target() how to remove targets that have not been added via device_add(). Reported-by:
Dariusz Majchrzak <dariusz.majchrzak@intel.com> Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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Dan Williams authored
commit 57fc2e33 upstream. Rapid ata hotplug on a libsas controller results in cases where libsas is waiting indefinitely on eh to perform an ata probe. A race exists between scsi_schedule_eh() and scsi_restart_operations() in the case when scsi_restart_operations() issues i/o to other devices in the sas domain. When this happens the host state transitions from SHOST_RECOVERY (set by scsi_schedule_eh) back to SHOST_RUNNING and ->host_busy is non-zero so we put the eh thread to sleep even though ->host_eh_scheduled is active. Before putting the error handler to sleep we need to check if the host_state needs to return to SHOST_RECOVERY for another trip through eh. Since i/o that is released by scsi_restart_operations has been blocked for at least one eh cycle, this implementation allows those i/o's to run before another eh cycle starts to discourage hung task timeouts. Reported-by:
Tom Jackson <thomas.p.jackson@intel.com> Tested-by:
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Dan Williams authored
commit b17caa17 upstream. commit 198439e4 [SCSI] libsas: do not set res = 0 in sas_ex_discover_dev() commit 19252de6 [SCSI] libsas: fix wide port hotplug issues The above commits seem to have confused the return value of sas_ex_discover_dev which is non-zero on failure and sas_ex_join_wide_port which just indicates short circuiting discovery on already established ports. The result is random discovery failures depending on configuration. Calls to sas_ex_join_wide_port are the source of the trouble as its return value is errantly assigned to 'res'. Convert it to bool and stop returning its result up the stack. Tested-by:
Dan Melnic <dan.melnic@amd.com> Reported-by:
Jack Wang <jack_wang@usish.com> Signed-off-by:
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Dan Williams authored
commit 26f2f199 upstream. Continue running revalidation until no more broadcast devices are discovered. Fixes cases where re-discovery completes too early in a domain with multiple expanders with pending re-discovery events. Servicing BCNs can get backed up behind error recovery. Signed-off-by:
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Andreas Schwab authored
commit 9f5072d4 upstream. Commit d57af9b2 (taskstats: use real microsecond granularity for CPU times) renamed msecs_to_cputime to usecs_to_cputime, but failed to update all numbers on the way. This causes nonsensical cpu idle/iowait values to be displayed in /proc/stat (the only user of usecs_to_cputime so far). This also renames __cputime_msec_factor to __cputime_usec_factor, adapting its value and using it directly in cputime_to_usecs instead of doing two multiplications. Signed-off-by:
Andreas Schwab <schwab@linux-m68k.org> Acked-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by:
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Tiejun Chen authored
commit b416c9a1 upstream. Add "memory" attribute in inline assembly language as a compiler barrier to make sure 4.6.x GCC don't reorder mfmsr(). Signed-off-by:
Tiejun Chen <tiejun.chen@windriver.com> Signed-off-by:
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roger blofeld authored
commit fd5a4298 upstream. Just like the module loader, ftrace needs to be updated to use r12 instead of r11 with newer gcc's. Signed-off-by:
Roger Blofeld <blofeldus@yahoo.com> Signed-off-by:
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Daniel Drake authored
commit 55fc05b7 upstream. At http://dev.laptop.org/ticket/11980 we have determined that the Marvell CaFe SDHCI controller reports bad card presence during resume. It reports that no card is present even when it is. This is a regression -- resume worked back around 2.6.37. Around 400ms after resuming, a "card inserted" interrupt is generated, at which point it starts reporting presence. Work around this hardware oddity by setting the SDHCI_QUIRK_BROKEN_CARD_DETECTION flag. Thanks to Chris Ball for helping with diagnosis. Signed-off-by:
Daniel Drake <dsd@laptop.org> Signed-off-by:
Chris Ball <cjb@laptop.org> Signed-off-by:
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- 01 Aug, 2012 13 commits
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Greg Kroah-Hartman authored
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Konstantin Khlebnikov authored
commit 635697c6 upstream. Stable note: The commit [acf92b48: vmscan: shrinker->nr updates race and go wrong] aimed to reduce excessive reclaim of slab objects but had bug in how it treated shrinker functions that returned -1. A shrinker function can return -1, means that it cannot do anything without a risk of deadlock. For example prune_super() does this if it cannot grab a superblock refrence, even if nr_to_scan=0. Currently we interpret this -1 as a ULONG_MAX size shrinker and evaluate `total_scan' according to this. So the next time around this shrinker can cause really big pressure. Let's skip such shrinkers instead. Also make total_scan signed, otherwise the check (total_scan < 0) below never works. Signed-off-by:
Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Mel Gorman <mgorman@suse.de> Signed-off-by:
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Konstantin Khlebnikov authored
commit b1c12cbc upstream. Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely expensive and severely impacted page allocator performance. This is part of a series of patches that reduce page allocator overhead. Fix a gcc warning (and bug?) introduced in cc9a6c87 ("cpuset: mm: reduce large amounts of memory barrier related damage v3") Local variable "page" can be uninitialized if the nodemask from vma policy does not intersects with nodemask from cpuset. Even if it doesn't happens it is better to initialize this variable explicitly than to introduce a kernel oops in a weird corner case. mm/hugetlb.c: In function `alloc_huge_page': mm/hugetlb.c:1135:5: warning: `page' may be used uninitialized in this function Signed-off-by:
David Rientjes <rientjes@google.com> Signed-off-by:
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Mel Gorman authored
commit cc9a6c87 upstream. Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely expensive and severely impacted page allocator performance. This is part of a series of patches that reduce page allocator overhead. Commit c0ff7453 ("cpuset,mm: fix no node to alloc memory when changing cpuset's mems") wins a super prize for the largest number of memory barriers entered into fast paths for one commit. [get|put]_mems_allowed is incredibly heavy with pairs of full memory barriers inserted into a number of hot paths. This was detected while investigating at large page allocator slowdown introduced some time after 2.6.32. The largest portion of this overhead was shown by oprofile to be at an mfence introduced by this commit into the page allocator hot path. For extra style points, the commit introduced the use of yield() in an implementation of what looks like a spinning mutex. This patch replaces the full memory barriers on both read and write sides with a sequence counter with just read barriers on the fast path side. This is much cheaper on some architectures, including x86. The main bulk of the patch is the retry logic if the nodemask changes in a manner that can cause a false failure. While updating the nodemask, a check is made to see if a false failure is a risk. If it is, the sequence number gets bumped and parallel allocators will briefly stall while the nodemask update takes place. In a page fault test microbenchmark, oprofile samples from __alloc_pages_nodemask went from 4.53% of all samples to 1.15%. The actual results were 3.3.0-rc3 3.3.0-rc3 rc3-vanilla nobarrier-v2r1 Clients 1 UserTime 0.07 ( 0.00%) 0.08 (-14.19%) Clients 2 UserTime 0.07 ( 0.00%) 0.07 ( 2.72%) Clients 4 UserTime 0.08 ( 0.00%) 0.07 ( 3.29%) Clients 1 SysTime 0.70 ( 0.00%) 0.65 ( 6.65%) Clients 2 SysTime 0.85 ( 0.00%) 0.82 ( 3.65%) Clients 4 SysTime 1.41 ( 0.00%) 1.41 ( 0.32%) Clients 1 WallTime 0.77 ( 0.00%) 0.74 ( 4.19%) Clients 2 WallTime 0.47 ( 0.00%) 0.45 ( 3.73%) Clients 4 WallTime 0.38 ( 0.00%) 0.37 ( 1.58%) Clients 1 Flt/sec/cpu 497620.28 ( 0.00%) 520294.53 ( 4.56%) Clients 2 Flt/sec/cpu 414639.05 ( 0.00%) 429882.01 ( 3.68%) Clients 4 Flt/sec/cpu 257959.16 ( 0.00%) 258761.48 ( 0.31%) Clients 1 Flt/sec 495161.39 ( 0.00%) 517292.87 ( 4.47%) Clients 2 Flt/sec 820325.95 ( 0.00%) 850289.77 ( 3.65%) Clients 4 Flt/sec 1020068.93 ( 0.00%) 1022674.06 ( 0.26%) MMTests Statistics: duration Sys Time Running Test (seconds) 135.68 132.17 User+Sys Time Running Test (seconds) 164.2 160.13 Total Elapsed Time (seconds) 123.46 120.87 The overall improvement is small but the System CPU time is much improved and roughly in correlation to what oprofile reported (these performance figures are without profiling so skew is expected). The actual number of page faults is noticeably improved. For benchmarks like kernel builds, the overall benefit is marginal but the system CPU time is slightly reduced. To test the actual bug the commit fixed I opened two terminals. The first ran within a cpuset and continually ran a small program that faulted 100M of anonymous data. In a second window, the nodemask of the cpuset was continually randomised in a loop. Without the commit, the program would fail every so often (usually within 10 seconds) and obviously with the commit everything worked fine. With this patch applied, it also worked fine so the fix should be functionally equivalent. Signed-off-by:
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David Rientjes authored
commit b246272e upstream. Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely expensive and severely impacted page allocator performance. This is part of a series of patches that reduce page allocator overhead. Kernels where MAX_NUMNODES > BITS_PER_LONG may temporarily see an empty nodemask in a tsk's mempolicy if its previous nodemask is remapped onto a new set of allowed cpuset nodes where the two nodemasks, as a result of the remap, are now disjoint. c0ff7453 ("cpuset,mm: fix no node to alloc memory when changing cpuset's mems") adds get_mems_allowed() to prevent the set of allowed nodes from changing for a thread. This causes any update to a set of allowed nodes to stall until put_mems_allowed() is called. This stall is unncessary, however, if at least one node remains unchanged in the update to the set of allowed nodes. This was addressed by 89e8a244 ("cpusets: avoid looping when storing to mems_allowed if one node remains set"), but it's still possible that an empty nodemask may be read from a mempolicy because the old nodemask may be remapped to the new nodemask during rebind. To prevent this, only avoid the stall if there is no mempolicy for the thread being changed. This is a temporary solution until all reads from mempolicy nodemasks can be guaranteed to not be empty without the get_mems_allowed() synchronization. Also moves the check for nodemask intersection inside task_lock() so that tsk->mems_allowed cannot change. This ensures that nothing can set this tsk's mems_allowed out from under us and also protects tsk->mempolicy. Reported-by:
Miao Xie <miaox@cn.fujitsu.com> Signed-off-by:
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David Rientjes authored
commit 89e8a244 upstream. Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely expensive and severely impacted page allocator performance. This is part of a series of patches that reduce page allocator overhead. {get,put}_mems_allowed() exist so that general kernel code may locklessly access a task's set of allowable nodes without having the chance that a concurrent write will cause the nodemask to be empty on configurations where MAX_NUMNODES > BITS_PER_LONG. This could incur a significant delay, however, especially in low memory conditions because the page allocator is blocking and reclaim requires get_mems_allowed() itself. It is not atypical to see writes to cpuset.mems take over 2 seconds to complete, for example. In low memory conditions, this is problematic because it's one of the most imporant times to change cpuset.mems in the first place! The only way a task's set of allowable nodes may change is through cpusets by writing to cpuset.mems and when attaching a task to a generic code is not reading the nodemask with get_mems_allowed() at the same time, and then clearing all the old nodes. This prevents the possibility that a reader will see an empty nodemask at the same time the writer is storing a new nodemask. If at least one node remains unchanged, though, it's possible to simply set all new nodes and then clear all the old nodes. Changing a task's nodemask is protected by cgroup_mutex so it's guaranteed that two threads are not changing the same task's nodemask at the same time, so the nodemask is guaranteed to be stored before another thread changes it and determines whether a node remains set or not. Signed-off-by:
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Johannes Weiner authored
commit b95a2f2d upstream - WARNING: this is a substitute patch. Stable note: Not tracked in Bugzilla. This is a partial backport of an upstream commit addressing a completely different issue that accidentally contained an important fix. The workload this patch helps was memcached when IO is started in the background. memcached should stay resident but without this patch it gets swapped. Sometimes this manifests as a drop in throughput but mostly it was observed through /proc/vmstat. Commit [246e87a9: memcg: fix get_scan_count() for small targets] was meant to fix a problem whereby small scan targets on memcg were ignored causing priority to raise too sharply. It forced scanning to take place if the target was small, memcg or kswapd. From the time it was introduced it caused excessive reclaim by kswapd with workloads being pushed to swap that previously would have stayed resident. This was accidentally fixed in commit [b95a2f2d: mm: vmscan: convert global reclaim to per-memcg LRU lists] by making it harder for kswapd to force scan small targets but that patchset is not suitable for backporting. This was later changed again by commit [90126375: mm/vmscan: push lruvec pointer into get_scan_count()] into a format that looks like it would be a straight-forward backport but there is a subtle difference due to the use of lruvecs. The impact of the accidental fix is to make it harder for kswapd to force scan small targets by taking zone->all_unreclaimable into account. This patch is the closest equivalent available based on what is backported. Signed-off-by:
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Hugh Dickins authored
commit 043bcbe5 upstream. Stable note: Not tracked in Bugzilla. There were reports of shared mapped pages being unfairly reclaimed in comparison to older kernels. This is being addressed over time. Even though the subject refers to lumpy reclaim, it impacts compaction as well. Lumpy reclaim does well to stop at a PageAnon when there's no swap, but better is to stop at any PageSwapBacked, which includes shmem/tmpfs too. Signed-off-by:
Hugh Dickins <hughd@google.com> Reviewed-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by:
Minchan Kim <minchan@kernel.org> Signed-off-by:
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Minchan Kim authored
commit 86cfd3a4 upstream. Stable note: Not tracked in Bugzilla. This patch reduces kswapd CPU usage on swapless systems with high anonymous memory usage. It's pointless to continue reclaiming when we have no swap space and lots of anon pages in the inactive list. Without this patch, it is possible when swap is disabled to continue trying to reclaim when there are only anonymous pages in the system even though that will not make any progress. Signed-off-by:
Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by:
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Konstantin Khlebnikov authored
commit c909e993 upstream. Stable note: Not tracked in Bugzilla. There were reports of shared mapped pages being unfairly reclaimed in comparison to older kernels. This is being addressed over time. Logic added in commit 8cab4754 ("vmscan: make mapped executable pages the first class citizen") was noticeably weakened in commit 64574746 ("vmscan: detect mapped file pages used only once"). Currently these pages can become "first class citizens" only after second usage. After this patch page_check_references() will activate they after first usage, and executable code gets yet better chance to stay in memory. Signed-off-by:
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Konstantin Khlebnikov authored
commit 34dbc67a upstream. Stable note: Not tracked in Bugzilla. There were reports of shared mapped pages being unfairly reclaimed in comparison to older kernels. This is being addressed over time. The specific workload being addressed here in described in paragraph four and while paragraph five says it did not help performance as such, it made a difference to major page faults. I'm aware of at least one bug for a large vendor that was due to increased major faults. Commit 64574746 ("vmscan: detect mapped file pages used only once") greatly decreases lifetime of single-used mapped file pages. Unfortunately it also decreases life time of all shared mapped file pages. Because after commit bf3f3bc5 ("mm: don't mark_page_accessed in fault path") page-fault handler does not mark page active or even referenced. Thus page_check_references() activates file page only if it was used twice while it stays in inactive list, meanwhile it activates anon pages after first access. Inactive list can be small enough, this way reclaimer can accidentally throw away any widely used page if it wasn't used twice in short period. After this patch page_check_references() also activate file mapped page at first inactive list scan if this page is already used multiple times via several ptes. I found this while trying to fix degragation in rhel6 (~2.6.32) from rhel5 (~2.6.18). There a complete mess with >100 web/mail/spam/ftp containers, they share all their files but there a lot of anonymous pages: ~500mb shared file mapped memory and 15-20Gb non-shared anonymous memory. In this situation major-pagefaults are very costly, because all containers share the same page. In my load kernel created a disproportionate pressure on the file memory, compared with the anonymous, they equaled only if I raise swappiness up to 150 =) These patches actually wasn't helped a lot in my problem, but I saw noticable (10-20 times) reduce in count and average time of major-pagefault in file-mapped areas. Actually both patches are fixes for commit v2.6.33-5448-g64574746, because it was aimed at one scenario (singly used pages), but it breaks the logic in other scenarios (shared and/or executable pages) Signed-off-by:
Pekka Enberg <penberg@kernel.org> Acked-by:
Minchan Kim <minchan.kim@gmail.com> Reviewed-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by:
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Mel Gorman authored
commit 0cee34fd upstream. Stable note: Not tracked on Bugzilla. THP and compaction was found to aggressively reclaim pages and stall systems under different situations that was addressed piecemeal over time. If compaction can proceed for a given zone, shrink_zones() does not reclaim any more pages from it. After commit [e0c23279: vmscan: abort reclaim/compaction if compaction can proceed], do_try_to_free_pages() tries to finish as soon as possible once one zone can compact. This was intended to prevent slabs being shrunk unnecessarily but there are side-effects. One is that a small zone that is ready for compaction will abort reclaim even if the chances of successfully allocating a THP from that zone is small. It also means that reclaim can return too early even though sc->nr_to_reclaim pages were not reclaimed. This partially reverts the commit until it is proven that slabs are really being shrunk unnecessarily but preserves the check to return 1 to avoid OOM if reclaim was aborted prematurely. [aarcange@redhat.com: This patch replaces a revert from Andrea] Signed-off-by:
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Mel Gorman authored
commit 7335084d upstream. Stable note: Not tracked in Bugzilla. This patch makes later patches easier to apply but otherwise has little to justify it. The problem it fixes was never observed but the source of the theoretical problem did not exist for very long. During direct reclaim it is possible that reclaim will be aborted so that compaction can be attempted to satisfy a high-order allocation. If this decision is made before any pages are reclaimed, it is possible that 0 is returned to the page allocator potentially triggering an OOM. This has not been observed but it is a possibility so this patch addresses it. Signed-off-by:
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