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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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Now that we have added breaks in the wait queue scan and allow bookmark
on scan position, we put this logic in the wake_up_page_bit function.
We can have very long page wait list in large system where multiple
pages share the same wait list. We break the wake up walk here to allow
other cpus a chance to access the list, and not to disable the interrupts
when traversing the list for too long. This reduces the interrupt and
rescheduling latency, and excessive page wait queue lock hold time.
[ v2: Remove bookmark_wake_function ]
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We encountered workloads that have very long wake up list on large
systems. A waker takes a long time to traverse the entire wake list and
execute all the wake functions.
We saw page wait list that are up to 3700+ entries long in tests of
large 4 and 8 socket systems. It took 0.8 sec to traverse such list
during wake up. Any other CPU that contends for the list spin lock will
spin for a long time. It is a result of the numa balancing migration of
hot pages that are shared by many threads.
Multiple CPUs waking are queued up behind the lock, and the last one
queued has to wait until all CPUs did all the wakeups.
The page wait list is traversed with interrupt disabled, which caused
various problems. This was the original cause that triggered the NMI
watch dog timer in: https://patchwork.kernel.org/patch/9800303/ . Only
extending the NMI watch dog timer there helped.
This patch bookmarks the waker's scan position in wake list and break
the wake up walk, to allow access to the list before the waker resume
its walk down the rest of the wait list. It lowers the interrupt and
rescheduling latency.
This patch also provides a performance boost when combined with the next
patch to break up page wakeup list walk. We saw 22% improvement in the
will-it-scale file pread2 test on a Xeon Phi system running 256 threads.
[ v2: Merged in Linus' changes to remove the bookmark_wake_function, and
simply access to flags. ]
Reported-by: Kan Liang <kan.liang@intel.com>
Tested-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf fixes from Ingo Molnar:
"A handful of tooling fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf stat: Wait for the correct child
perf tools: Support running perf binaries with a dash in their name
perf config: Check not only section->from_system_config but also item's
perf ui progress: Fix progress update
perf ui progress: Make sure we always define step value
perf tools: Open perf.data with O_CLOEXEC flag
tools lib api: Fix make DEBUG=1 build
perf tests: Fix compile when libunwind's unwind.h is available
tools include linux: Guard against redefinition of some macros
Pull scheduler fixes from Ingo Molnar:
"Three CPU hotplug related fixes and a debugging improvement"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Add debugfs knob for "sched_debug"
sched/core: WARN() when migrating to an offline CPU
sched/fair: Plug hole between hotplug and active_load_balance()
sched/fair: Avoid newidle balance for !active CPUs
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
- Fix TUI progress bar when delta from new total from that of the
previous update is greater than the progress "step" (screen width
progress bar block)) (Jiri Olsa)
- Make tools/lib/api make DEBUG=1 build use -D_FORTIFY_SOURCE=2 not
to cripple debuginfo, just like tools/perf/ does (Jiri Olsa)
- Avoid leaking the 'perf.data' file to workloads started from the
'perf record' command line by using the O_CLOEXEC open flag (Jiri Olsa)
- Fix building when libunwind's 'unwind.h' file is present in the
include path, clashing with tools/perf/util/unwind.h (Milian Wolff)
- Check per .perfconfig section entry flag, not just per section (Taeung Song)
- Support running perf binaries with a dash in their name, needed to
run perf as an AppImage (Milian Wolff)
- Wait for the right child by using waitpid() when running workloads
from 'perf stat', also to fix using perf as an AppImage (Milian Wolff)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"The main changes are the PCID fixes from Andy, but there's also two
hyperv fixes and two paravirt updates"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/hyper-v: Remove duplicated HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED definition
x86/hyper-V: Allocate the IDT entry early in boot
paravirt: Switch maintainer
x86/paravirt: Remove no longer used paravirt functions
x86/mm/64: Initialize CR4.PCIDE early
x86/hibernate/64: Mask off CR3's PCID bits in the saved CR3
x86/mm: Get rid of VM_BUG_ON in switch_tlb_irqs_off()
I'm forever late for editing my kernel cmdline, add a runtime knob to
disable the "sched_debug" thing.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170907150614.142924283@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've mostly tuned f2fs to provide better user
experience for Android. Especially, we've worked on atomic write
feature again with SQLite community in order to support it officially.
And we added or modified several facilities to analyze and enhance IO
behaviors.
Major changes include:
- add app/fs io stat
- add inode checksum feature
- support project/journalled quota
- enhance atomic write with new ioctl() which exposes feature set
- enhance background gc/discard/fstrim flows with new gc_urgent mode
- add F2FS_IOC_FS{GET,SET}XATTR
- fix some quota flows"
* tag 'f2fs-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (63 commits)
f2fs: hurry up to issue discard after io interruption
f2fs: fix to show correct discard_granularity in sysfs
f2fs: detect dirty inode in evict_inode
f2fs: clear radix tree dirty tag of pages whose dirty flag is cleared
f2fs: speed up gc_urgent mode with SSR
f2fs: better to wait for fstrim completion
f2fs: avoid race in between read xattr & write xattr
f2fs: make get_lock_data_page to handle encrypted inode
f2fs: use generic terms used for encrypted block management
f2fs: introduce f2fs_encrypted_file for clean-up
Revert "f2fs: add a new function get_ssr_cost"
f2fs: constify super_operations
f2fs: fix to wake up all sleeping flusher
f2fs: avoid race in between atomic_read & atomic_inc
f2fs: remove unneeded parameter of change_curseg
f2fs: update i_flags correctly
f2fs: don't check inode's checksum if it was dirtied or writebacked
f2fs: don't need to update inode checksum for recovery
f2fs: trigger fdatasync for non-atomic_write file
f2fs: fix to avoid race in between aio and gc
...
When packaging the perf userland application into an AppImage, the
wait() call in perf stat returned too early. It turned out that some
other child process exited, but not the one perf stat launched:
$ sudo strace -e fork,execve,clone,wait4 -f ./perf-x86_64.AppImage stat sleep 1
execve("./perf-git.3a73b7f9-x86_64.AppImage", ["./perf-git.3a73b7f9-x86_64.AppIm"..., "stat", "sleep", "1"], 0x7ffec1bbf050 /* 18 vars */) = 0
clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f6a6e7efe50) = 3912
strace: Process 3912 attached
[pid 3912] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f6a6e7efe50) = 3914
strace: Process 3914 attached
[pid 3912] +++ exited with 0 +++
[pid 3911] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=3912, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
[pid 3914] clone(strace: Process 3915 attached
child_stack=0x7f6a6d9fefb0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7f6a6d9ff9d0, tls=0x7f6a6d9ff700, child_tidptr=0x7f6a6d9ff9d0) = 3915
[pid 3911] execve("/tmp/.mount_perf-g6VYMpl/AppRun", ["./perf-git.3a73b7f9-x86_64.AppIm"..., "stat", "sleep", "1"], 0x14aab70 /* 21 vars */) = 0
[pid 3911] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f4ae113c4d0) = 3916
strace: Process 3916 attached
[pid 3911] wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 3912
[pid 3916] execve("/usr/libexec/perf-core/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/tmp/./sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/home/milian/.bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/usr/lib/icecream/libexec/icecc/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/ssd2/milian/projects/compiled/other/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/home/milian/.bin/kf5/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/ssd2/milian/projects/compiled/kf5/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/home/milian/projects/compiled/other/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/home/milian/projects/compiled/kf5/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/usr/local/sbin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/usr/local/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
[pid 3916] execve("/usr/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */
Performance counter stats for 'sleep 1':
<not counted> task-clock
<not counted> context-switches
<not counted> cpu-migrations
<not counted> page-faults
<not counted> cycles
<not counted> instructions
<not counted> branches
<not counted> branch-misses
0.000047194 seconds time elapsed
[pid 3916] --- SIGTERM {si_signo=SIGTERM, si_code=SI_USER, si_pid=3911, si_uid=0} ---
[pid 3916] +++ killed by SIGTERM +++
[pid 3911] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=3916, si_uid=0, si_status=SIGTERM, si_utime=0, si_stime=0} ---
[pid 3915] --- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=3914, si_uid=0} ---
[pid 3911] +++ exited with 0 +++
[pid 3915] --- SIGHUP {si_signo=SIGHUP, si_code=SI_USER, si_pid=3914, si_uid=0} ---
[pid 3915] +++ exited with 0 +++
+++ exited with 0 +++
This patch uses waitpid instead to ensure the call waits for the
debuggee application launched by 'perf stat'. This fixes 'perf stat'
when launched from an AppImage:
$ ./perf-x86_64.AppImage stat sleep 1
Performance counter stats for 'sleep 1':
0.357235 task-clock (msec) # 0.000 CPUs utilized
1 context-switches # 0.003 M/sec
0 cpu-migrations # 0.000 K/sec
50 page-faults # 0.140 M/sec
1269602 cycles # 3.554 GHz
654278 instructions # 0.52 insn per cycle
129963 branches # 363.803 M/sec
7082 branch-misses # 5.45% of all branches
1.000633420 seconds time elapsed
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170912152523.4497-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull OpenRISC fixlet from Stafford Horne:
"Fix warning for upcoming work to remove linux/vmalloc.h from
asm-generic/io.h"
* tag 'openrisc-for-linus' of git://github.com/openrisc/linux:
openrisc: add forward declaration for struct vm_area_struct
Commits:
7dcf90e9e032 ("PCI: hv: Use vPCI protocol version 1.2")
628f54cc6451 ("x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls")
added the same definition and they came in through different trees.
Fix the duplication.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170911150620.3998-1-vkuznets@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Migrating tasks to offline CPUs is a pretty big fail, warn about it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170907150614.094206976@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull ceph updates from Ilya Dryomov:
"The highlights include:
- a large series of fixes and improvements to the snapshot-handling
code (Zheng Yan)
- individual read/write OSD requests passed down to libceph are now
limited to 16M in size to avoid hitting OSD-side limits (Zheng Yan)
- encode MStatfs v2 message to allow for more accurate space usage
reporting (Douglas Fuller)
- switch to the new writeback error tracking infrastructure (Jeff
Layton)"
* tag 'ceph-for-4.14-rc1' of git://github.com/ceph/ceph-client: (35 commits)
ceph: stop on-going cached readdir if mds revokes FILE_SHARED cap
ceph: wait on writeback after writing snapshot data
ceph: fix capsnap dirty pages accounting
ceph: ignore wbc->range_{start,end} when write back snapshot data
ceph: fix "range cyclic" mode writepages
ceph: cleanup local variables in ceph_writepages_start()
ceph: optimize pagevec iterating in ceph_writepages_start()
ceph: make writepage_nounlock() invalidate page that beyonds EOF
ceph: properly get capsnap's size in get_oldest_context()
ceph: remove stale check in ceph_invalidatepage()
ceph: queue cap snap only when snap realm's context changes
ceph: handle race between vmtruncate and queuing cap snap
ceph: fix message order check in handle_cap_export()
ceph: fix NULL pointer dereference in ceph_flush_snaps()
ceph: adjust 36 checks for NULL pointers
ceph: delete an unnecessary return statement in update_dentry_lease()
ceph: ENOMEM pr_err in __get_or_create_frag() is redundant
ceph: check negative offsets in ceph_llseek()
ceph: more accurate statfs
ceph: properly set snap follows for cap reconnect
...
Once we encounter I/O interruption during issuing discards, we will delay
long time before next round, but if system status is I/O idle during the
time, it may loses opportunity to issue discards. So this patch changes
to hurry up to issue discard after io interruption.
Besides, this patch also fixes to issue discards accurately with assigned
rate.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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