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* Merge tag 'sched-core-2023-04-27' of ↵Linus Torvalds2023-04-281-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Allow unprivileged PSI poll()ing - Fix performance regression introduced by mm_cid - Improve livepatch stalls by adding livepatch task switching to cond_resched(). This resolves livepatching busy-loop stalls with certain CPU-bound kthreads - Improve sched_move_task() performance on autogroup configs - On core-scheduling CPUs, avoid selecting throttled tasks to run - Misc cleanups, fixes and improvements * tag 'sched-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/clock: Fix local_clock() before sched_clock_init() sched/rt: Fix bad task migration for rt tasks sched: Fix performance regression introduced by mm_cid sched/core: Make sched_dynamic_mutex static sched/psi: Allow unprivileged polling of N*2s period sched/psi: Extract update_triggers side effect sched/psi: Rename existing poll members in preparation sched/psi: Rearrange polling code in preparation sched/fair: Fix inaccurate tally of ttwu_move_affine vhost: Fix livepatch timeouts in vhost_worker() livepatch,sched: Add livepatch task switching to cond_resched() livepatch: Skip task_call_func() for current task livepatch: Convert stack entries array to percpu sched: Interleave cfs bandwidth timers for improved single thread performance at low utilization sched/core: Reduce cost of sched_move_task when config autogroup sched/core: Avoid selecting the task that is throttled to run when core-sched enable sched/topology: Make sched_energy_mutex,update static
| * sched/psi: Allow unprivileged polling of N*2s periodDomenico Cerasuolo2023-04-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PSI offers 2 mechanisms to get information about a specific resource pressure. One is reading from /proc/pressure/<resource>, which gives average pressures aggregated every 2s. The other is creating a pollable fd for a specific resource and cgroup. The trigger creation requires CAP_SYS_RESOURCE, and gives the possibility to pick specific time window and threshold, spawing an RT thread to aggregate the data. Systemd would like to provide containers the option to monitor pressure on their own cgroup and sub-cgroups. For example, if systemd launches a container that itself then launches services, the container should have the ability to poll() for pressure in individual services. But neither the container nor the services are privileged. This patch implements a mechanism to allow unprivileged users to create pressure triggers. The difference with privileged triggers creation is that unprivileged ones must have a time window that's a multiple of 2s. This is so that we can avoid unrestricted spawning of rt threads, and use instead the same aggregation mechanism done for the averages, which runs independently of any triggers. Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20230330105418.77061-5-cerasuolodomenico@gmail.com
* | delayacct: track delays from IRQ/SOFTIRQYang Yang2023-04-191-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Delay accounting does not track the delay of IRQ/SOFTIRQ. While IRQ/SOFTIRQ could have obvious impact on some workloads productivity, such as when workloads are running on system which is busy handling network IRQ/SOFTIRQ. Get the delay of IRQ/SOFTIRQ could help users to reduce such delay. Such as setting interrupt affinity or task affinity, using kernel thread for NAPI etc. This is inspired by "sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure"[1]. Also fix some code indent problems of older code. And update tools/accounting/getdelays.c: / # ./getdelays -p 156 -di print delayacct stats ON printing IO accounting PID 156 CPU count real total virtual total delay total delay average 15 15836008 16218149 275700790 18.380ms IO count delay total delay average 0 0 0.000ms SWAP count delay total delay average 0 0 0.000ms RECLAIM count delay total delay average 0 0 0.000ms THRASHING count delay total delay average 0 0 0.000ms COMPACT count delay total delay average 0 0 0.000ms WPCOPY count delay total delay average 36 7586118 0.211ms IRQ count delay total delay average 42 929161 0.022ms [1] commit 52b1364ba0b1("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure") Link: https://lkml.kernel.org/r/202304081728353557233@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Cc: Jiang Xuexin <jiang.xuexin@zte.com.cn> Cc: wangyong <wang.yong12@zte.com.cn> Cc: junhua huang <huang.junhua@zte.com.cn> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | delayacct: improve the average delay precision of getdelay tool to microsecondWang Yong2023-04-081-7/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | Improve the average delay precision of getdelay tool to microsecond. When using the getdelay tool, it is sometimes found that the average delay except CPU is not 0, but display is 0, because the precison is too low. For example, see delay average of SWAP below when using ZRAM. print delayacct stats ON PID 32915 CPU count real total virtual total delay total delay average 339202 2793871936 9233585504 7951112 0.000ms IO count delay total delay average 41 419296904 10ms SWAP count delay total delay average 242589 1045792384 0ms This wrong display is misleading, so improve the millisecond precision of the average delay to microsecond just like CPU. Then user would get more accurate information of delay time. Link: https://lkml.kernel.org/r/202302131408087983857@zte.com.cn Signed-off-by: Wang Yong <wang.yong12@zte.com.cn> Reviewed-by: Yang Yang <yang.yang29@zte.com.cn> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* filemap: make the accounting of thrashing more consistentYang Yang2022-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | Once upon a time, we only support accounting thrashing of page cache. Then Joonsoo introduced workingset detection for anonymous pages and we gained the ability to account thrashing of them[1]. So let delayacct account both the thrashing of page cache and anonymous pages, this could make the codes more consistent and simpler. [1] commit aae466b0052e ("mm/swap: implement workingset detection for anonymous LRU") Link: https://lkml.kernel.org/r/20220805033838.1714674-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: CGEL ZTE <cgel.zte@gmail.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Yang Yang <yang.yang29@zte.com.cn> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* delayacct: track delays from write-protect copyYang Yang2022-06-021-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Delay accounting does not track the delay of write-protect copy. When tasks trigger many write-protect copys(include COW and unsharing of anonymous pages[1]), it may spend a amount of time waiting for them. To get the delay of tasks in write-protect copy, could help users to evaluate the impact of using KSM or fork() or GUP. Also update tools/accounting/getdelays.c: / # ./getdelays -dl -p 231 print delayacct stats ON listen forever PID 231 CPU count real total virtual total delay total delay average 6247 1859000000 2154070021 1674255063 0.268ms IO count delay total delay average 0 0 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 0 0 0ms THRASHING count delay total delay average 0 0 0ms COMPACT count delay total delay average 3 72758 0ms WPCOPY count delay total delay average 3635 271567604 0ms [1] commit 31cc5bc4af70("mm: support GUP-triggered unsharing of anonymous pages") Link: https://lkml.kernel.org/r/20220409014342.2505532-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jiang Xuexin <jiang.xuexin@zte.com.cn> Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Reviewed-by: wangyong <wang.yong12@zte.com.cn> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* sched/psi: report zeroes for CPU full at the system levelChengming Zhou2022-04-221-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Martin find it confusing when look at the /proc/pressure/cpu output, and found no hint about that CPU "full" line in psi Documentation. % cat /proc/pressure/cpu some avg10=0.92 avg60=0.91 avg300=0.73 total=933490489 full avg10=0.22 avg60=0.23 avg300=0.16 total=358783277 The PSI_CPU_FULL state is introduced by commit e7fcd7622823 ("psi: Add PSI_CPU_FULL state"), which mainly for cgroup level, but also counted at the system level as a side effect. Naturally, the FULL state doesn't exist for the CPU resource at the system level. These "full" numbers can come from CPU idle schedule latency. For example, t1 is the time when task wakeup on an idle CPU, t2 is the time when CPU pick and switch to it. The delta of (t2 - t1) will be in CPU_FULL state. Another case all processes can be stalled is when all cgroups have been throttled at the same time, which unlikely to happen. Anyway, CPU_FULL metric is meaningless and confusing at the system level. So this patch will report zeroes for CPU full at the system level, and update psi Documentation accordingly. Fixes: e7fcd7622823 ("psi: Add PSI_CPU_FULL state") Reported-by: Martin Steigerwald <Martin.Steigerwald@proact.de> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20220408121914.82855-1-zhouchengming@bytedance.com
* Merge tag 'sched_urgent_for_v5.17_rc2' of ↵Linus Torvalds2022-01-231-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Borislav Petkov: "A bunch of fixes: forced idle time accounting, utilization values propagation in the sched hierarchies and other minor cleanups and improvements" * tag 'sched_urgent_for_v5.17_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kernel/sched: Remove dl_boosted flag comment sched: Avoid double preemption in __cond_resched_*lock*() sched/fair: Fix all kernel-doc warnings sched/core: Accounting forceidle time for all tasks except idle task sched/pelt: Relax the sync of load_sum with load_avg sched/pelt: Relax the sync of runnable_sum with runnable_avg sched/pelt: Continue to relax the sync of util_sum with util_avg sched/pelt: Relax the sync of util_sum with util_avg psi: Fix uaf issue when psi trigger is destroyed while being polled
| * psi: Fix uaf issue when psi trigger is destroyed while being polledSuren Baghdasaryan2022-01-181-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With write operation on psi files replacing old trigger with a new one, the lifetime of its waitqueue is totally arbitrary. Overwriting an existing trigger causes its waitqueue to be freed and pending poll() will stumble on trigger->event_wait which was destroyed. Fix this by disallowing to redefine an existing psi trigger. If a write operation is used on a file descriptor with an already existing psi trigger, the operation will fail with EBUSY error. Also bypass a check for psi_disabled in the psi_trigger_destroy as the flag can be flipped after the trigger is created, leading to a memory leak. Fixes: 0e94682b73bf ("psi: introduce psi monitor") Reported-by: syzbot+cdb5dd11c97cc532efad@syzkaller.appspotmail.com Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Analyzed-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220111232309.1786347-1-surenb@google.com
* | Documentation/accounting/delay-accounting.rst: add thrashing page cache and ↵wangyong2022-01-201-28/+27
|/ | | | | | | | | | | | | | | | | | | | | | direct compact Add thrashing page cache and direct compact related descriptions and update the usage of getdelays userspace utility. The following patches modifications have been updated: https://lore.kernel.org/all/20190312102002.31737-4-jinpuwang@gmail.com/ https://lore.kernel.org/all/1638619795-71451-1-git-send-email- wang.yong12@zte.com.cn/ Link: https://lkml.kernel.org/r/1639583021-92977-1-git-send-email-wang.yong12@zte.com.cn Signed-off-by: wangyong <wang.yong12@zte.com.cn> Reviewed-by: Yang Yang <yang.yang29@zte.com.cn> Reported-by: Zeal Robot <zealci@zte.com.cn> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* delayacct: Add sysctl to enable at runtimePeter Zijlstra2021-05-121-2/+4
| | | | | | | | | Just like sched_schedstats, allow runtime enabling (and disabling) of delayacct. This is useful if one forgot to add the delayacct boot time option. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YJkhebGJAywaZowX@hirez.programming.kicks-ass.net
* delayacct: Default disabledPeter Zijlstra2021-05-121-4/+4
| | | | | | | | | | | | | | Assuming this stuff isn't actually used much; disable it by default and avoid allocating and tracking the task_delay_info structure. taskstats is changed to still report the regular sched and sched_info and only skip the missing task_delay_info fields instead of not reporting anything. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210505111525.308018373@infradead.org
* Documentation: Replace lkml.org links with loreJoe Perches2021-01-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the lkml.org links with lore to better use a single source that's more likely to stay available long-term. Done by bash script: cvt_lkml_to_lore () { tmpfile=$(mktemp ./.cvt_links.XXXXXXX) header=$(echo $1 | sed 's@/lkml/@/lkml/headers/@') wget -qO - $header > $tmpfile if [[ $? == 0 ]] ; then link=$(grep -i '^Message-Id:' $tmpfile | head -1 | \ sed -r -e 's/^\s*Message-Id:\s*<\s*//' -e 's/\s*>\s*$//' -e 's@^@https://lore.kernel.org/r/@') # echo "testlink: $link" if [ -n "$link" ] ; then wget -qO - $link > /dev/null if [[ $? == 0 ]] ; then echo $link fi fi fi rm -f $tmpfile } git grep -P -o "\bhttps?://(?:www.)?lkml.org/lkml[\/\w]+" $@ | while read line ; do echo $line file=$(echo $line | cut -f1 -d':') link=$(echo $line | cut -f2- -d':') newlink=$(cvt_lkml_to_lore $link) if [[ -n "$newlink" ]] ; then sed -i -e "s#\b$link\b#$newlink#" $file fi done Link: https://lore.kernel.org/patchwork/patch/1265849/#1462688 Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/77cdb7f32cfb087955bfc3600b86c40bed5d4104.camel@perches.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* doc: cgroup: improve formatting of referencesJakub Kicinski2020-03-021-0/+2
| | | | | | | | | Annotate references to other documents to make them clickable. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20200228000653.1572553-6-kuba@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* docs: add some documentation dirs to the driver-api bookMauro Carvalho Chehab2019-07-151-1/+1
| | | | | | | | Those are subsystem docs, with a mix of kABI and user-faced docs. While they're not split, keep the dirs where they are, adding just a pointer to the main index. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: accounting: convert to ReSTMauro Carvalho Chehab2019-07-156-89/+136
| | | | | | | | | | | Rename the accounting documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* psi: introduce psi monitorSuren Baghdasaryan2019-05-151-0/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Psi monitor aims to provide a low-latency short-term pressure detection mechanism configurable by users. It allows users to monitor psi metrics growth and trigger events whenever a metric raises above user-defined threshold within user-defined time window. Time window and threshold are both expressed in usecs. Multiple psi resources with different thresholds and window sizes can be monitored concurrently. Psi monitors activate when system enters stall state for the monitored psi metric and deactivate upon exit from the stall state. While system is in the stall state psi signal growth is monitored at a rate of 10 times per tracking window. Min window size is 500ms, therefore the min monitoring interval is 50ms. Max window size is 10s with monitoring interval of 1s. When activated psi monitor stays active for at least the duration of one tracking window to avoid repeated activations/deactivations when psi signal is bouncing. Notifications to the users are rate-limited to one per tracking window. Link: http://lkml.kernel.org/r/20190319235619.260832-8-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Li Zefan <lizefan@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* psi: clarify the units used in pressure filesWaiman Long2019-04-061-6/+6
| | | | | | | | | | | | | | | | | The output of the PSI files show a bunch of numbers with no unit. The psi.txt documentation file also does not indicate what units are used. One can only find out by looking at the source code. The units are percentage for the averages and useconds for the total. Make the information easier to find by documenting the units in psi.txt. Link: http://lkml.kernel.org/r/20190402193810.3450-1-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* psi: cgroup supportJohannes Weiner2018-10-271-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a system that executes multiple cgrouped jobs and independent workloads, we don't just care about the health of the overall system, but also that of individual jobs, so that we can ensure individual job health, fairness between jobs, or prioritize some jobs over others. This patch implements pressure stall tracking for cgroups. In kernels with CONFIG_PSI=y, cgroup2 groups will have cpu.pressure, memory.pressure, and io.pressure files that track aggregate pressure stall times for only the tasks inside the cgroup. Link: http://lkml.kernel.org/r/20180828172258.3185-10-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* psi: pressure stall information for CPU, memory, and IOJohannes Weiner2018-10-271-0/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tools: move accounting tool from DocumentationShuah Khan2016-09-234-561/+3
| | | | | | | | | | | | Move accounting tool to tools and remove it from Documentation Makefile. Update location information for this tool. Create a new Makefile to build accounting. It can be built from top level directory or from accounting directory: Run make -C tools/accounting or cd tools/accounting; make Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
* taskstats: fix nl parsing in accounting/getdelays.cNicolas Dichtel2016-04-271-1/+4
| | | | | | | | | | | | | | The type TASKSTATS_TYPE_NULL should always be ignored. When jumping to the next attribute, only the length of the current attribute should be added, not the length of all nested attributes. This last bug was not visible before commit 80df554275c2, because the kernel didn't put more than two nested attributes. Fixes: a3baf649ca9c ("[PATCH] per-task-delay-accounting: documentation") Fixes: 80df554275c2 ("taskstats: use the libnl API to align nlattr on 64-bit") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Documentation-getdelays: Apply a recommendation from "checkpatch.pl" in main()Markus Elfring2015-12-241-1/+2
| | | | | | | | | The script "checkpatch.pl" pointed out that assignments should usually not be performed within condition checks. Thus move the assignment for the variable "nl_sd" to a separate statement. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: use subdir-y to avoid unnecessary built-in.o filesPeter Foley2014-09-261-3/+0
| | | | | | | | | | | Change the Documentation makefiles from obj-m to subdir-y to avoid generating unnecessary built-in.o files since nothing in Documentation/ is ever linked in to vmlinux. Signed-off-by: Peter Foley <pefoley2@pefoley.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Documentation/accounting/getdelays.c: add missing null-terminate after ↵Rickard Strandqvist2014-06-241-0/+1
| | | | | | | | | | | | | | strncpy call Added a guaranteed null-terminate after call to strncpy. This was partly found using a static code analysis program called cppcheck. Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/accounting/getdelays.c: avoid strncpy in accounting toolKees Cook2013-07-041-2/+2
| | | | | | | | | | | Avoid strncpy anti-pattern. [akpm@linux-foundation.org: remove the str[cpy|dup] altogether] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* doc: Remove unnecessary declarations from Documentation/accounting/getdelays.cAnthony G. Basile2012-11-261-1/+0
| | | | | | | | | | | stime and utime are declared __u64 but are never used. On a glibc system this is harmless lint, but on a uClibc system, because of the difference in they way header files stack, including stdio.h brings in time.h and this causes a name collision with stime. Since these are useless anyhow, we remove them. Signed-off-by: Anthony G. Basile <basile@opensource.dyc.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* doc: getdelays.c: remember to close() socket on error in create_nl_socket()Jesper Juhl2012-09-011-3/+2
| | | | | | | | | | | | | | | | | If the call to setsockopt() fails in Documentation/accounting/getdelays.c::create_nl_socket() we return -1 without closing the socket, thus leaking it when the 'fd' variable goes out of scope. Easily fixed by just jumping to the 'error' label instead of returning since we do the proper cleanup there. While I was there I noticed that the error message that is printet if setsockopt() fails was broken over two lines - put that on a single line so it is easier to grep for. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Documentation: update cgroupfs mount pointJörg Sommer2011-06-161-2/+2
| | | | | | | | | | | According to commit 676db4af0430 ("cgroupfs: create /sys/fs/cgroup to mount cgroupfs on") the canonical mountpoint for the cgroup filesystem is /sys/fs/cgroup. Hence, this should be used in the documentation. Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* getdelays: show average CPU/IO/SWAP/RECLAIM delaysWu Fengguang2011-05-271-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | I find it very handy to show the average delays in milliseconds. Example output (on 100 concurrent dd reading sparse files): CPU count real total virtual total delay total delay average 986 3223509952 3207643301 38863410579 39.415ms IO count delay total delay average 0 0 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 1059 5131834899 4ms dd: read=0, write=0, cancelled_write=0 Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Mel Gorman <mel@linux.vnet.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Reviewed-by: Satoru Moriya <satoru.moriya@hds.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/accounting/getdelays.c: handle sendto() failuresAndrew Morton2011-05-271-0/+2
| | | | | | | | | | | | Fixes Documentation/accounting/getdelays.c: In function `get_family_id': Documentation/accounting/getdelays.c:172:14: warning: variable `rc' set but not used [-Wunused-but-set-variable] Reported-by: "Justin P. Mattock" <justinmattock@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/accounting/getdelays.c: fix unused var warningJustin P. Mattock2011-05-271-3/+0
| | | | | | | | | | | | Fixes Documentation/accounting/getdelays.c: In function `main': Documentation/accounting/getdelays.c:436:7: warning: variable `i' set but not used [-Wunused-but-set-variable] Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* taskstats: pad taskstats netlink response for aligment issues on ia64Jeff Mahoney2010-12-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The taskstats structure is internally aligned on 8 byte boundaries but the layout of the aggregrate reply, with two NLA headers and the pid (each 4 bytes), actually force the entire structure to be unaligned. This causes the kernel to issue unaligned access warnings on some architectures like ia64. Unfortunately, some software out there doesn't properly unroll the NLA packet and assumes that the start of the taskstats structure will always be 20 bytes from the start of the netlink payload. Aligning the start of the taskstats structure breaks this software, which we don't want. So, for now the alignment only happens on architectures that require it and those users will have to update to fixed versions of those packages. Space is reserved in the packet only when needed. This ifdef should be removed in several years e.g. 2012 once we can be confident that fixed versions are installed on most systems. We add the padding before the aggregate since the aggregate is already a defined type. Commit 85893120 ("delayacct: align to 8 byte boundary on 64-bit systems") previously addressed the alignment issues by padding out the pid field. This was supposed to be a compatible change but the circumstances described above mean that it wasn't. This patch backs out that change, since it was a hack, and introduces a new NULL attribute type to provide the padding. Padding the response with 4 bytes avoids allocating an aligned taskstats structure and copying it back. Since the structure weighs in at 328 bytes, it's too big to do it on the stack. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reported-by: Brian Rogers <brian@xyzw.org> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Guillaume Chazarain <guichaz@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* delay-accounting: reimplement -c for getdelays.c to report information on a ↵Mel Gorman2010-10-281-2/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | target command Task delay-accounting was identified as one means of determining how long a process spends in congestion_wait() without adding new statistics. For example, if the workload should not be doing IO, delay-accounting could reveal how long it was spending in unexpected IO or delays. Unfortunately, on closer examination it was clear that getdelays does not act as documented. Commit a3baf649 ("per-task-delay-accounting: documentation") added Documentation/accounting/getdelays.c with a -c switch that was documented to fork/exec a child and report statistics on it but for reasons that are unclear to me, commit 9e06d3f9 deleted support for this switch but did not update the documentation. It might be an oversight or it might be because the control flow of the program meant that accounting information would be printed once early in the lifetime of the program making it of limited use. This patch reimplements -c for getdelays.c to act as documented. Unlike the original version, it waits until the command completes before printing any information on it. An example of it being used looks like $ ./getdelays -d -c find /home/mel -name mel print delayacct stats ON /home/mel /home/mel/.notes-wine/drive_c/windows/profiles/mel /home/mel/.wine/drive_c/windows/profiles/mel /home/mel/git-configs/dot.kde/share/apps/konqueror/home/mel PID 5923 CPU count real total virtual total delay total 42779 5051232096 5164722692 564207988 IO count delay total 41727 97804147758 SWAP count delay total 0 0 RECLAIM count delay total 0 0 [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGSLadinu Chandrasinghe2009-09-231-6/+6
| | | | | | | | | | | Fix up -Wmissing-prototypes in compileable userspace code, mainly under Documentation/. Signed-off-by: Ladinu Chandrasinghe <ladinu.pub@gmail.com> Signed-off-by: Trevor Keith <tsrk@tsrk.net> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/accounting/getdelays.c intialize the variable before using itJaswinder Singh Rajput2009-06-171-1/+2
| | | | | | | | | | | | | | Fix compilation warning: Documentation/accounting/getdelays.c: In function `main': Documentation/accounting/getdelays.c:249: warning: `cmd_type' may be used uninitialized in this function This is in fact a false positive. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Acked-by: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/accounting/getdelays.c: fix endless loopMarcus Meissner2009-01-161-0/+4
| | | | | | | | | | | When no option is passed to getdelays it just hangs, waiting for a reply which will never come. This patch prints usage() when no output marker is specified. Signed-off-by: Marcus Meissner <meissner@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* .gitignore updatesAlexey Dobriyan2008-10-301-0/+1
| | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* docsrc: fix getdelays printk formatsRandy Dunlap2008-08-131-8/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | Fix printf format type warnings (seen on alpha & ia64): Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 6 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 7 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 8 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 9 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 12 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 13 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 16 has type '__u64' Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 17 has type '__u64' Documentation/accounting/getdelays.c:214: warning: format '%15llu' expects type 'long long unsigned int', but argument 4 has type '__u64' Documentation/accounting/getdelays.c:214: warning: format '%15llu' expects type 'long long unsigned int', but argument 5 has type '__u64' Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 2 has type '__u64' Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type '__u64' Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 4 has type '__u64' Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 5 has type '__u64' Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 6 has type '__u64' Documentation/accounting/getdelays.c:236: warning: 'cmd_type' may be used uninitialized in this function Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* docsrc: build Documentation/ sourcesRandy Dunlap2008-08-131-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | Currently source files in the Documentation/ sub-dir can easily bit-rot since they are not generally buildable, either because they are hidden in text files or because there are no Makefile rules for them. This needs to be fixed so that the source files remain usable and good examples of code instead of bad examples. Add the ability to build source files that are in the Documentation/ dir. Add to Kconfig as "BUILD_DOCSRC" config symbol. Use "CONFIG_BUILD_DOCSRC=1 make ..." to build objects from the Documentation/ sources. Or enable BUILD_DOCSRC in the *config system. However, this symbol depends on HEADERS_CHECK since the header files need to be installed (for userspace builds). Built (using cross-tools) for x86-64, i386, alpha, ia64, sparc32, sparc64, powerpc, sh, m68k, & mips. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation cleanup: trivial misspelling, punctuation, and grammar ↵Matt LaPlante2008-07-261-1/+1
| | | | | | | | corrections. Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* per-task-delay-accounting: update document and getdelays.c for memory reclaimKeika Kobayashi2008-07-252-5/+14
| | | | | | | | | | | | | Update document and make getdelays.c show delay accounting for memory reclaim. For making a distinction between "swapping in pages" and "memory reclaim" in getdelays.c, MEM is changed to SWAP. Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* per-task-delay-accounting: update taskstats for memory reclaim delayKeika Kobayashi2008-07-251-0/+7
| | | | | | | | | | | Add members for memory reclaim delay to taskstats, and accumulate them in __delayacct_add_tsk() . Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Update taskstats-struct document for scaled time accountingHiroshi Shimamoto2008-07-041-0/+6
| | | | | | | | | Update Documentation/accounting/taskstats-struct.txt for TASKSTATS_VERSION 6, adding scaled time accounting. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* getdelays: fix gcc warningsRandy Dunlap2008-02-081-3/+3
| | | | | | | | | | | | | | | | | | | | | Fix gcc warnings in getdelays.c: Documentation/accounting/getdelays.c: In function 'task_context_switch_counts': Documentation/accounting/getdelays.c:214: warning: format '%15lu' expects type 'long unsigned int', but argument 4 has type '__u64' Documentation/accounting/getdelays.c:214: warning: format '%15lu' expects type 'long unsigned int', but argument 5 has type '__u64' Documentation/accounting/getdelays.c: In function 'main': Documentation/accounting/getdelays.c:402: warning: format '%d' expects type 'int', but argument 2 has type 'long unsigned int' Documentation/accounting/getdelays.c: In function 'get_family_id': Documentation/accounting/getdelays.c:171: warning: 'id' may be used uninitialized in this function One warning is not a problem and can be dismissed: Documentation/accounting/getdelays.c: In function 'main': Documentation/accounting/getdelays.c:236: warning: 'cmd_type' may be used uninitialized in this function Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make getdelays cgroupstats awareBalbir Singh2007-11-151-1/+42
| | | | | | | | | | Update the getdelays utility to become cgroupstats aware. A new -C option has been added. It takes in a control group path and prints out a summary of the states of tasks in the control group Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add cgroupstatsBalbir Singh2007-10-191-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is inspired by the discussion at http://lkml.org/lkml/2007/4/11/187 and implements per cgroup statistics as suggested by Andrew Morton in http://lkml.org/lkml/2007/4/11/263. The patch is on top of 2.6.21-mm1 with Paul's cgroups v9 patches (forward ported) This patch implements per cgroup statistics infrastructure and re-uses code from the taskstats interface. A new set of cgroup operations are registered with commands and attributes. It should be very easy to *extend* per cgroup statistics, by adding members to the cgroupstats structure. The current model for cgroupstats is a pull, a push model (to post statistics on interesting events), should be very easy to add. Currently user space requests for statistics by passing the cgroup file descriptor. Statistics about the state of all the tasks in the cgroup is returned to user space. TODO's/NOTE: This patch provides an infrastructure for implementing cgroup statistics. Based on the needs of each controller, we can incrementally add more statistics, event based support for notification of statistics, accumulation of taskstats into cgroup statistics in the future. Sample output # ./cgroupstats -C /cgroup/a sleeping 2, blocked 0, running 1, stopped 0, uninterruptible 0 # ./cgroupstats -C /cgroup/ sleeping 154, blocked 0, running 0, stopped 0, uninterruptible 0 If the approach looks good, I'll enhance and post the user space utility for the same Feedback, comments, test results are always welcome! [akpm@linux-foundation.org: build fix] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Clean up duplicate includes in Documentation/Jesper Juhl2007-10-171-1/+0
| | | | | | | | | | This patch cleans up duplicate includes in Documentation/ Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation: fix getdelays.c printf bugMichael Neuling2007-08-231-1/+1
| | | | | | | | | | | Commit b663a79c191508f27cd885224b592a878c0ba0f6 ("taskstats: add context-switch counters") incorrectly removed a comma from a printf statement. This causes corruption in the output printing or a seg fault. Signed-off-by: Michael Neuling <mikey@neuling.org> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* taskstats: add context-switch countersMaxim Uvarov2007-07-162-2/+23
| | | | | | | | | | | | | | | | | | | | | | | Make available to the user the following task and process performance statistics: * Involuntary Context Switches (task_struct->nivcsw) * Voluntary Context Switches (task_struct->nvcsw) Statistics information is available from: 1. taskstats interface (Documentation/accounting/) 2. /proc/PID/status (task only). This data is useful for detecting hyperactivity patterns between processes. [akpm@linux-foundation.org: cleanup] Signed-off-by: Maxim Uvarov <muvarov@ru.mvista.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Jonathan Lim <jlim@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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