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2020-05-19sched/cpuacct: Fix charge cpuacct.usage_sysMuchun Song
The user_mode(task_pt_regs(tsk)) always return true for user thread, and false for kernel thread. So it means that the cpuacct.usage_sys is the time that kernel thread uses not the time that thread uses in the kernel mode. We can try get_irq_regs() first, if it is NULL, then we can fall back to task_pt_regs(). Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200420070453.76815-1-songmuchun@bytedance.com
2020-05-19sched/cpuacct: Use __this_cpu_add() instead of this_cpu_ptr()Muchun Song
The cpuacct_charge() and cpuacct_account_field() are called with rq->lock held, and this means preemption(and IRQs) are indeed disabled, so it is safe to use __this_cpu_*() to allow for better code-generation. Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200507031039.32615-1-songmuchun@bytedance.com
2018-03-04sched/headers: Simplify and clean up header usage in the schedulerIngo Molnar
Do the following cleanups and simplifications: - sched/sched.h already includes <asm/paravirt.h>, so no need to include it in sched/core.c again. - order the <linux/sched/*.h> headers alphabetically - add all <linux/sched/*.h> headers to kernel/sched/sched.h - remove all unnecessary includes from the .c files that are already included in kernel/sched/sched.h. Finally, make all scheduler .c files use a single common header: #include "sched.h" ... which now contains a union of the relied upon headers. This makes the various .c files easier to read and easier to handle. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-03sched: Clean up and harmonize the coding style of the scheduler code baseIngo Molnar
A good number of small style inconsistencies have accumulated in the scheduler core, so do a pass over them to harmonize all these details: - fix speling in comments, - use curly braces for multi-line statements, - remove unnecessary parentheses from integer literals, - capitalize consistently, - remove stray newlines, - add comments where necessary, - remove invalid/unnecessary comments, - align structure definitions and other data types vertically, - add missing newlines for increased readability, - fix vertical tabulation where it's misaligned, - harmonize preprocessor conditional block labeling and vertical alignment, - remove line-breaks where they uglify the code, - add newline after local variable definitions, No change in functionality: md5: 1191fa0a890cfa8132156d2959d7e9e2 built-in.o.before.asm 1191fa0a890cfa8132156d2959d7e9e2 built-in.o.after.asm Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01sched/cputime: Convert kcpustat to nsecsFrederic Weisbecker
Kernel CPU stats are stored in cputime_t which is an architecture defined type, and hence a bit opaque and requiring accessors and mutators for any operation. Converting them to nsecs simplifies the code and is one step toward the removal of cputime_t in the core code. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-16sched/cpuacct: Avoid %lld seq_printf warningMartin Schwidefsky
For s390 kernel builds I keep getting this warning: kernel/sched/cpuacct.c: In function 'cpuacct_stats_show': kernel/sched/cpuacct.c:298:25: warning: format '%lld' expects argument of type 'long long int', but argument 4 has type 'clock_t {aka long int}' [-Wformat=] seq_printf(sf, "%s %lld\n", Silence the warning by adding an explicit cast. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> 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/20161111142749.6545-1-schwidefsky@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-09sched/cpuacct: Introduce cpuacct.usage_all to show all CPU stats togetherZhao Lei
In current code, we can get cpuacct data from several files, but each file has various limitations. For example: - We can get CPU usage in user and kernel mode via cpuacct.stat, but we can't get detailed data about each CPU. - We can get each CPU's kernel mode usage in cpuacct.usage_percpu_sys, but we can't get user mode usage data at the same time. This patch introduces cpuacct.usage_all, to show all detailed CPU accounting data together: # cat cpuacct.usage_all cpu user system 0 3809760299 5807968992 1 3250329855 454612211 .. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> 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/7744460969edd7caaf0e903592ee52353ed9bdd6.1466415271.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-09sched/cpuacct: Use loop to consolidate code in cpuacct_stats_show()Zhao Lei
In cpuacct_stats_show() we currently we have copies of similar code, for each cpustat(system/user) variant. Use a loop instead to consolidate the code. This will also work better if we extend the CPUACCT_STAT_NSTATS type. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> 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/b0597d4224655e9f333f1a6224ed9654c7d7d36a.1466415271.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-09sched/cpuacct: Merge cpuacct_usage_index and cpuacct_stat_index enumsZhao Lei
These two types have similar function, no need to separate them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> 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/436748885270d64363c7dc67167507d486c2057a.1466415271.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13sched/cpuacct: Check for NULL when using task_pt_regs()Anton Blanchard
task_pt_regs() can return NULL for kernel threads, so add a check. This fixes an oops at boot on ppc64. Reported-and-Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: efault@gmx.de Cc: htejun@gmail.com Cc: linuxppc-dev@lists.ozlabs.org Cc: tj@kernel.org Cc: yangds.fnst@cn.fujitsu.com Link: http://lkml.kernel.org/r/20160406215950.04bc3f0b@kryten Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31sched/cpuacct: Split usage accounting into user_usage and sys_usageDongsheng Yang
Sometimes, cpuacct.usage is not detailed enough to see how much CPU usage a group had. We want to know how much time it used in user mode and how much in kernel mode. This patch introduces more files to give this information: # ls /sys/fs/cgroup/cpuacct/cpuacct.usage* /sys/fs/cgroup/cpuacct/cpuacct.usage /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu /sys/fs/cgroup/cpuacct/cpuacct.usage_user /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu_user /sys/fs/cgroup/cpuacct/cpuacct.usage_sys /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu_sys ... while keeping the ABI with the existing counter. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> [ Ported to newer kernels. ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <htejun@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/aa171da036b520b51c79549e9b3215d29473f19d.1458635566.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31sched/cpuacct: Show all possible CPUs in cpuacct outputZhao Lei
Current code show stats of online CPUs in cpuacct.statcpus, show stats of present cpus in cpuacct.usage(_percpu), and using present CPUs for setting cpuacct.usage. It will cause inconsistent result when a CPU is online or offline or hotpluged. We should always use possible CPUs to avoid above problem. Here are the contents of a cpuacct.usage_percpu sysfs file, on a 4 CPU system with maxcpus=32: Before the patch: # cat cpuacct.usage_percpu 2456565 411435 1052897 832584 After the patch: # cat cpuacct.usage_percpu 2456565 411435 1052897 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Tejun Heo <htejun@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a11d56cef12d0b4807f8be3a46bf9798c3014d59.1458635566.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-24Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixes: a cgroup fix, a fair-scheduler migration accounting fix, a cputime fix and two cpuacct cleanups" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/cpuacct: Simplify the cpuacct code sched/cpuacct: Rename parameter in cpuusage_write() for readability sched/fair: Add comments to explain select_idle_sibling() sched/fair: Fix fairness issue on migration sched/cgroup: Fix/cleanup cgroup teardown/init sched/cputime: Fix steal time accounting vs. CPU hotplug
2016-03-21sched/cpuacct: Simplify the cpuacct codeZhao Lei
- Use for() instead of while() loop in some functions to make the code simpler. - Use this_cpu_ptr() instead of per_cpu_ptr() to make the code cleaner and a bit faster. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tejun Heo <htejun@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/d8a7ef9592f55224630cb26dea239f05b6398a4e.1458187654.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-21sched/cpuacct: Rename parameter in cpuusage_write() for readabilityDongsheng Yang
The name of the 'reset' parameter to cpuusage_write() is quite confusing, because the only valid value we allow is '0', so !reset is actually the case that resets ... Rename it to 'val' and explain it in a comment that we only allow 0. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: cgroups@vger.kernel.org Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1450696483-2864-1-git-send-email-yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-23cgroup: convert cgroup_subsys flag fields to bool bitfieldsTejun Heo
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
2014-07-15cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypesTejun Heo
Currently, cgroup_subsys->base_cftypes is used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through. cgroup_subsys will grow two separate cftype arrays and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch renames cgroup_subsys->base_cftypes to cgroup_subsys->legacy_cftypes. This patch is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Aristeu Rozanski <aris@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2014-05-16cgroup: remove css_parent()Tejun Heo
cgroup in general is moving towards using cgroup_subsys_state as the fundamental structural component and css_parent() was introduced to convert from using cgroup->parent to css->parent. It was quite some time ago and we're moving forward with making css more prominent. This patch drops the trivial wrapper css_parent() and let the users dereference css->parent. While at it, explicitly mark fields of css which are public and immutable. v2: New usage from device_cgroup.c converted. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Johannes Weiner <hannes@cmpxchg.org>
2014-02-08cgroup: clean up cgroup_subsys names and initializationTejun Heo
cgroup_subsys is a bit messier than it needs to be. * The name of a subsys can be different from its internal identifier defined in cgroup_subsys.h. Most subsystems use the matching name but three - cpu, memory and perf_event - use different ones. * cgroup_subsys_id enums are postfixed with _subsys_id and each cgroup_subsys is postfixed with _subsys. cgroup.h is widely included throughout various subsystems, it doesn't and shouldn't have claim on such generic names which don't have any qualifier indicating that they belong to cgroup. * cgroup_subsys->subsys_id should always equal the matching cgroup_subsys_id enum; however, we require each controller to initialize it and then BUG if they don't match, which is a bit silly. This patch cleans up cgroup_subsys names and initialization by doing the followings. * cgroup_subsys_id enums are now postfixed with _cgrp_id, and each cgroup_subsys with _cgrp_subsys. * With the above, renaming subsys identifiers to match the userland visible names doesn't cause any naming conflicts. All non-matching identifiers are renamed to match the official names. cpu_cgroup -> cpu mem_cgroup -> memory perf -> perf_event * controllers no longer need to initialize ->subsys_id and ->name. They're generated in cgroup core and set automatically during boot. * Redundant cgroup_subsys declarations removed. * While updating BUG_ON()s in cgroup_init_early(), convert them to WARN()s. BUGging that early during boot is stupid - the kernel can't print anything, even through serial console and the trap handler doesn't even link stack frame properly for back-tracing. This patch doesn't introduce any behavior changes. v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs classid handling into core"). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Ingo Molnar <mingo@redhat.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Thomas Graf <tgraf@suug.ch>
2013-12-05cgroup: replace cftype->read_seq_string() with cftype->seq_show()Tejun Heo
In preparation of conversion to kernfs, cgroup file handling is updated so that it can be easily mapped to kernfs. This patch replaces cftype->read_seq_string() with cftype->seq_show() which is not limited to single_open() operation and will map directcly to kernfs seq_file interface. The conversions are mechanical. As ->seq_show() doesn't have @css and @cft, the functions which make use of them are converted to use seq_css() and seq_cft() respectively. In several occassions, e.f. if it has seq_string in its name, the function name is updated to fit the new method better. This patch does not introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Aristeu Rozanski <arozansk@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Neil Horman <nhorman@tuxdriver.com>
2013-12-05cgroup, sched: convert away from cftype->read_map()Tejun Heo
In preparation of conversion to kernfs, cgroup file handling is being consolidated so that it can be easily mapped to the seq_file based interface of kernfs. cftype->read_map() doesn't add any value and being replaced with ->read_seq_string(). Update cpu_stats_show() and cpuacct_stats_show() accordingly. This patch doesn't make any visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
2013-08-08cgroup: pass around cgroup_subsys_state instead of cgroup in file methodsTejun Heo
cgroup is currently in the process of transitioning to using struct cgroup_subsys_state * as the primary handle instead of struct cgroup. Please see the previous commit which converts the subsystem methods for rationale. This patch converts all cftype file operations to take @css instead of @cgroup. cftypes for the cgroup core files don't have their subsytem pointer set. These will automatically use the dummy_css added by the previous patch and can be converted the same way. Most subsystem conversions are straight forwards but there are some interesting ones. * freezer: update_if_frozen() is also converted to take @css instead of @cgroup for consistency. This will make the code look simpler too once iterators are converted to use css. * memory/vmpressure: mem_cgroup_from_css() needs to be exported to vmpressure while mem_cgroup_from_cont() can be made static. Updated accordingly. * cpu: cgroup_tg() doesn't have any user left. Removed. * cpuacct: cgroup_ca() doesn't have any user left. Removed. * hugetlb: hugetlb_cgroup_form_cgroup() doesn't have any user left. Removed. * net_cls: cgrp_cls_state() doesn't have any user left. Removed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Steven Rostedt <rostedt@goodmis.org>
2013-08-08cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methodsTejun Heo
cgroup is currently in the process of transitioning to using struct cgroup_subsys_state * as the primary handle instead of struct cgroup * in subsystem implementations for the following reasons. * With unified hierarchy, subsystems will be dynamically bound and unbound from cgroups and thus css's (cgroup_subsys_state) may be created and destroyed dynamically over the lifetime of a cgroup, which is different from the current state where all css's are allocated and destroyed together with the associated cgroup. This in turn means that cgroup_css() should be synchronized and may return NULL, making it more cumbersome to use. * Differing levels of per-subsystem granularity in the unified hierarchy means that the task and descendant iterators should behave differently depending on the specific subsystem the iteration is being performed for. * In majority of the cases, subsystems only care about its part in the cgroup hierarchy - ie. the hierarchy of css's. Subsystem methods often obtain the matching css pointer from the cgroup and don't bother with the cgroup pointer itself. Passing around css fits much better. This patch converts all cgroup_subsys methods to take @css instead of @cgroup. The conversions are mostly straight-forward. A few noteworthy changes are * ->css_alloc() now takes css of the parent cgroup rather than the pointer to the new cgroup as the css for the new cgroup doesn't exist yet. Knowing the parent css is enough for all the existing subsystems. * In kernel/cgroup.c::offline_css(), unnecessary open coded css dereference is replaced with local variable access. This patch shouldn't cause any behavior differences. v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced with local variable @css as suggested by Li Zefan. Rebased on top of new for-3.12 which includes for-3.11-fixes so that ->css_free() invocation added by da0a12caff ("cgroup: fix a leak when percpu_ref_init() fails") is converted too. Suggested by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Steven Rostedt <rostedt@goodmis.org>
2013-08-08cgroup: add css_parent()Tejun Heo
Currently, controllers have to explicitly follow the cgroup hierarchy to find the parent of a given css. cgroup is moving towards using cgroup_subsys_state as the main controller interface construct, so let's provide a way to climb the hierarchy using just csses. This patch implements css_parent() which, given a css, returns its parent. The function is guarnateed to valid non-NULL parent css as long as the target css is not at the top of the hierarchy. freezer, cpuset, cpu, cpuacct, hugetlb, memory, net_cls and devices are converted to use css_parent() instead of accessing cgroup->parent directly. * __parent_ca() is dropped from cpuacct and its usage is replaced with parent_ca(). The only difference between the two was NULL test on cgroup->parent which is now embedded in css_parent() making the distinction moot. Note that eventually a css->parent field will be added to css and the NULL check in css_parent() will go away. This patch shouldn't cause any behavior differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-08-08cgroup: add/update accessors which obtain subsys specific data from cssTejun Heo
css (cgroup_subsys_state) is usually embedded in a subsys specific data structure. Subsystems either use container_of() directly to cast from css to such data structure or has an accessor function wrapping such cast. As cgroup as whole is moving towards using css as the main interface handle, add and update such accessors to ease dealing with css's. All accessors explicitly handle NULL input and return NULL in those cases. While this looks like an extra branch in the code, as all controllers specific data structures have css as the first field, the casting doesn't involve any offsetting and the compiler can trivially optimize out the branch. * blkio, freezer, cpuset, cpu, cpuacct and net_cls didn't have such accessor. Added. * memory, hugetlb and devices already had one but didn't explicitly handle NULL input. Updated. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-08-08cgroup: s/cgroup_subsys_state/cgroup_css/ s/task_subsys_state/task_css/Tejun Heo
The names of the two struct cgroup_subsys_state accessors - cgroup_subsys_state() and task_subsys_state() - are somewhat awkward. The former clashes with the type name and the latter doesn't even indicate it's somehow related to cgroup. We're about to revamp large portion of cgroup API, so, let's rename them so that they're less awkward. Most per-controller usages of the accessors are localized in accessor wrappers and given the amount of scheduled changes, this isn't gonna add any noticeable headache. Rename cgroup_subsys_state() to cgroup_css() and task_subsys_state() to task_css(). This patch is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-10sched/cpuacct/UML: Fix header file dependency bug on the UML buildIngo Molnar
The cpuacct split caused this build failure on UML: kernel/sched/cpuacct.c:94:2: error: implicit declaration of function 'ERR_PTR' Cc: Li Zefan <lizefan@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: No need to check subsys active stateLi Zefan
Now we're guaranteed when cpuacct_charge() and cpuacct_account_field() are called, cpuacct has already been properly initialized, so we no longer need those checks. Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/5155384C.7000508@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Initialize cpuacct subsystem earlierLi Zefan
Initialize cpuacct before the scheduler is functioning, so when cpuacct_charge() and cpuacct_account_field() are called, task_ca() won't return NULL. Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/5155383F.8000005@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Initialize root cpuacct earlierLi Zefan
Now we don't need cpuacct_init(), and instead we just initialize root_cpuacct when it's defined. Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51553834.9090701@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Allocate per_cpu cpuusage for root cpuacct staticallyLi Zefan
This is a preparation, so later we can initialize cpuacct earlier. Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51553822.5000403@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Clean up cpuacct.hLi Zefan
Now most of the code in cpuacct.h can be moved to cpuacct.c Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/515536D5.2080401@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Remove redundant NULL checks in cpuacct_acount_field()Li Zefan
This is a micro optimazation for a hot path. - We don't need to check if @ca returned from task_ca() is NULL. - We don't need to check if @ca returned from parent_ca() is NULL. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/515536B7.6060602@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Remove redundant NULL checks in cpuacct_charge()Li Zefan
This is a micro optimization for the hot path. - We don't need to check if @ca is NULL in parent_ca(). - We don't need to check if @ca is NULL in the beginning of the for loop. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/515536A9.5000700@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Add cpuacct_acount_field()Li Zefan
So we can remove open-coded cpuacct code in cputime.c. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51553692.9060008@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched/cpuacct: Add cpuacct_init()Li Zefan
So we don't open-coded initialization of cpuacct in core.c. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51553687.1060906@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-10sched: Split cpuacct code out of core.cLi Zefan
Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/5155366F.5060404@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>