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2019-03-12Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount infrastructure updates from Al Viro: "The rest of core infrastructure; no new syscalls in that pile, but the old parts are switched to new infrastructure. At that point conversions of individual filesystems can happen independently; some are done here (afs, cgroup, procfs, etc.), there's also a large series outside of that pile dealing with NFS (quite a bit of option-parsing stuff is getting used there - it's one of the most convoluted filesystems in terms of mount-related logics), but NFS bits are the next cycle fodder. It got seriously simplified since the last cycle; documentation is probably the weakest bit at the moment - I considered dropping the commit introducing Documentation/filesystems/mount_api.txt (cutting the size increase by quarter ;-), but decided that it would be better to fix it up after -rc1 instead. That pile allows to do followup work in independent branches, which should make life much easier for the next cycle. fs/super.c size increase is unpleasant; there's a followup series that allows to shrink it considerably, but I decided to leave that until the next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits) afs: Use fs_context to pass parameters over automount afs: Add fs_context support vfs: Add some logging to the core users of the fs_context log vfs: Implement logging through fs_context vfs: Provide documentation for new mount API vfs: Remove kern_mount_data() hugetlbfs: Convert to fs_context cpuset: Use fs_context kernfs, sysfs, cgroup, intel_rdt: Support fs_context cgroup: store a reference to cgroup_ns into cgroup_fs_context cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper cgroup_do_mount(): massage calling conventions cgroup: stash cgroup_root reference into cgroup_fs_context cgroup2: switch to option-by-option parsing cgroup1: switch to option-by-option parsing cgroup: take options parsing into ->parse_monolithic() cgroup: fold cgroup1_mount() into cgroup1_get_tree() cgroup: start switching to fs_context ipc: Convert mqueue fs to fs_context proc: Add fs_context support to procfs ...
2019-02-28cpuset: Use fs_contextDavid Howells
Make the cpuset filesystem use the filesystem context. This is potentially tricky as the cpuset fs is almost an alias for the cgroup filesystem, but with some special parameters. This can, however, be handled by setting up an appropriate cgroup filesystem and returning the root directory of that as the root dir of this one. Signed-off-by: David Howells <dhowells@redhat.com> cc: Tejun Heo <tj@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-19cpuset: remove unused task_has_mempolicy()Masahiro Yamada
This is a remnant of commit 5f155f27cb7f ("mm, cpuset: always use seqlock when changing task's nodemask"). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-12-29Merge branch 'for-4.21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - Waiman's cgroup2 cpuset support has been finally merged closing one of the last remaining feature gaps. - cgroup.procs could show non-leader threads when cgroup2 threaded mode was used in certain ways. I forgot to push the fix during the last cycle. - A patch to fix mount option parsing when all mount options have been consumed by someone else (LSM). - cgroup_no_v1 boot param can now block named cgroup1 hierarchies too. * 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Add named hierarchy disabling to cgroup_no_v1 boot param cgroup: fix parsing empty mount option string cpuset: Remove set but not used variable 'cs' cgroup: fix CSS_TASK_ITER_PROCS cgroup: Add .__DEBUG__. prefix to debug file names cpuset: Minor cgroup2 interface updates cpuset: Expose cpuset.cpus.subpartitions with cgroup_debug cpuset: Add documentation about the new "cpuset.sched.partition" flag cpuset: Use descriptive text when reading/writing cpuset.sched.partition cpuset: Expose cpus.effective and mems.effective on cgroup v2 root cpuset: Make generate_sched_domains() work with partition cpuset: Make CPU hotplug work with partition cpuset: Track cpusets that use parent's effective_cpus cpuset: Add an error state to cpuset.sched.partition cpuset: Add new v2 cpuset.sched.partition flag cpuset: Simply allocation and freeing of cpumasks cpuset: Define data structures to support scheduling partition cpuset: Enable cpuset controller in default hierarchy cgroup: remove unnecessary unlikely()
2018-12-28mm, oom: reorganize the oom report in dump_headeryuzhoujian
OOM report contains several sections. The first one is the allocation context that has triggered the OOM. Then we have cpuset context followed by the stack trace of the OOM path. The tird one is the OOM memory information. Followed by the current memory state of all system tasks. At last, we will show oom eligible tasks and the information about the chosen oom victim. One thing that makes parsing more awkward than necessary is that we do not have a single and easily parsable line about the oom context. This patch is reorganizing the oom report to 1) who invoked oom and what was the allocation request [ 515.902945] tuned invoked oom-killer: gfp_mask=0x6200ca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0 2) OOM stack trace [ 515.904273] CPU: 24 PID: 1809 Comm: tuned Not tainted 4.20.0-rc3+ #3 [ 515.905518] Hardware name: Inspur SA5212M4/YZMB-00370-107, BIOS 4.1.10 11/14/2016 [ 515.906821] Call Trace: [ 515.908062] dump_stack+0x5a/0x73 [ 515.909311] dump_header+0x55/0x28c [ 515.914260] oom_kill_process+0x2d8/0x300 [ 515.916708] out_of_memory+0x145/0x4a0 [ 515.917932] __alloc_pages_slowpath+0x7d2/0xa16 [ 515.919157] __alloc_pages_nodemask+0x277/0x290 [ 515.920367] filemap_fault+0x3d0/0x6c0 [ 515.921529] ? filemap_map_pages+0x2b8/0x420 [ 515.922709] ext4_filemap_fault+0x2c/0x40 [ext4] [ 515.923884] __do_fault+0x20/0x80 [ 515.925032] __handle_mm_fault+0xbc0/0xe80 [ 515.926195] handle_mm_fault+0xfa/0x210 [ 515.927357] __do_page_fault+0x233/0x4c0 [ 515.928506] do_page_fault+0x32/0x140 [ 515.929646] ? page_fault+0x8/0x30 [ 515.930770] page_fault+0x1e/0x30 3) OOM memory information [ 515.958093] Mem-Info: [ 515.959647] active_anon:26501758 inactive_anon:1179809 isolated_anon:0 active_file:4402672 inactive_file:483963 isolated_file:1344 unevictable:0 dirty:4886753 writeback:0 unstable:0 slab_reclaimable:148442 slab_unreclaimable:18741 mapped:1347 shmem:1347 pagetables:58669 bounce:0 free:88663 free_pcp:0 free_cma:0 ... 4) current memory state of all system tasks [ 516.079544] [ 744] 0 744 9211 1345 114688 82 0 systemd-journal [ 516.082034] [ 787] 0 787 31764 0 143360 92 0 lvmetad [ 516.084465] [ 792] 0 792 10930 1 110592 208 -1000 systemd-udevd [ 516.086865] [ 1199] 0 1199 13866 0 131072 112 -1000 auditd [ 516.089190] [ 1222] 0 1222 31990 1 110592 157 0 smartd [ 516.091477] [ 1225] 0 1225 4864 85 81920 43 0 irqbalance [ 516.093712] [ 1226] 0 1226 52612 0 258048 426 0 abrtd [ 516.112128] [ 1280] 0 1280 109774 55 299008 400 0 NetworkManager [ 516.113998] [ 1295] 0 1295 28817 37 69632 24 0 ksmtuned [ 516.144596] [ 10718] 0 10718 2622484 1721372 15998976 267219 0 panic [ 516.145792] [ 10719] 0 10719 2622484 1164767 9818112 53576 0 panic [ 516.146977] [ 10720] 0 10720 2622484 1174361 9904128 53709 0 panic [ 516.148163] [ 10721] 0 10721 2622484 1209070 10194944 54824 0 panic [ 516.149329] [ 10722] 0 10722 2622484 1745799 14774272 91138 0 panic 5) oom context (contrains and the chosen victim). oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0-1,task=panic,pid=10737,uid=0 An admin can easily get the full oom context at a single line which makes parsing much easier. Link: http://lkml.kernel.org/r/1542799799-36184-1-git-send-email-ufo19890607@gmail.com Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Yang Shi <yang.s@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-03cpuset: Remove set but not used variable 'cs'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: kernel/cgroup/cpuset.c: In function 'cpuset_cancel_attach': kernel/cgroup/cpuset.c:2167:17: warning: variable 'cs' set but not used [-Wunused-but-set-variable] It never used since introduction in commit 1f7dd3e5a6e4 ("cgroup: fix handling of multi-destination migration from subtree_control enabling") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-13cpuset: Minor cgroup2 interface updatesTejun Heo
* Rename the partition file from "cpuset.sched.partition" to "cpuset.cpus.partition". * When writing to the partition file, drop "0" and "1" and only accept "member" and "root". Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Waiman Long <longman@redhat.com>
2018-11-08cpuset: Expose cpuset.cpus.subpartitions with cgroup_debugWaiman Long
For debugging purpose, it will be useful to expose the content of the subparts_cpus as a read-only file to see if the code work correctly. However, subparts_cpus will not be used at all in most use cases. So adding a new cpuset file that clutters the cgroup directory may not be desirable. This is now being done by using the hidden "cgroup_debug" kernel command line option to expose a new "cpuset.cpus.subpartitions" file. That option was originally used by the debug controller to expose itself when configured into the kernel. This is now extended to set an internal flag used by cgroup_addrm_files(). A new CFTYPE_DEBUG flag can now be used to specify that a cgroup file should only be created when the "cgroup_debug" option is specified. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Use descriptive text when reading/writing cpuset.sched.partitionWaiman Long
Currently, cpuset.sched.partition returns the values, 0, 1 or -1 on read. A person who is not familiar with the partition code may not understand what they mean. In order to make cpuset.sched.partition more user-friendly, it will now display the following descriptive text on read: "root" - A partition root (top cpuset of a partition) "member" - A non-root member of a partition "root invalid" - An invalid partition root Note that there is at least one partition in the whole cgroup hierarchy. The top cpuset is the root of that partition. The rests are either a root if it starts a new partition or a member of a partition. The cpuset.sched.partition file will now also accept "root" and "member" besides 1 and 0 as valid input values. The "root invalid" value is internal only and cannot be written to the file. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Expose cpus.effective and mems.effective on cgroup v2 rootWaiman Long
Because of the fact that setting the "cpuset.sched.partition" in a direct child of root can remove CPUs from the root's effective CPU list, it makes sense to know what CPUs are left in the root cgroup for scheduling purpose. So the "cpuset.cpus.effective" control file is now exposed in the v2 cgroup root. For consistency, the "cpuset.mems.effective" control file is exposed as well. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Make generate_sched_domains() work with partitionWaiman Long
The generate_sched_domains() function is modified to make it work correctly with the newly introduced subparts_cpus mask for scheduling domains generation. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Make CPU hotplug work with partitionWaiman Long
When there is a cpu hotplug event (CPU online or offline), the partitions may need to be reconfigured and regenerated. So code is added to the hotplug functions to make them work with new subparts_cpus mask to compute the right effective_cpus for each of the affected cpusets. It may also change the state of a partition root from real one to an erroneous one or vice versa. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Track cpusets that use parent's effective_cpusWaiman Long
In the default hierarchy, a cpuset will use the parent's effective_cpus if none of the requested CPUs can be granted from the parent. That can be a problem if a parent is a partition root with children partition roots. Changes to a parent's effective_cpus list due to changes in a child partition root may not be properly reflected in a child cpuset that use parent's effective_cpus because the cpu_exclusive rule of a partition root will not guard against that. In order to avoid the mismatch, two new tracking variables are added to the cpuset structure to track if a cpuset uses parent's effective_cpus and the number of children cpusets that use its effective_cpus. So whenever cpumask changes are made to a parent, it will also check to see if it has other children cpusets that use its effective_cpus and call update_cpumasks_hier() if that is the case. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Add an error state to cpuset.sched.partitionWaiman Long
When external events like CPU offlining or user events like changing the cpu list of an ancestor cpuset happen, update_cpumasks_hier() will be called to update the effective cpus of each of the affected cpusets. That will then call update_parent_subparts_cpumask() if partitions are impacted. Currently, these events may cause update_parent_subparts_cpumask() to return error if none of the requested cpus are available or it will consume all the cpus in the parent partition root. Handling these errors is problematic as the states may become inconsistent. Instead of letting update_parent_subparts_cpumask() return error, a new error state (-1) is added to the partition_root_state flag to designate the fact that the partition is no longer valid. IOW, it is no longer a real partition root, but the CS_CPU_EXCLUSIVE flag will still be set as it can be changed back to a real one if favorable change happens later on. This new error state is set internally and user cannot write this new value to "cpuset.sched.partition". Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Add new v2 cpuset.sched.partition flagWaiman Long
A new cpuset.sched.partition boolean flag is added to cpuset v2. This new flag, if set, indicates that the cgroup is the root of a new scheduling domain or partition that includes itself and all its descendants except those that are scheduling domain roots themselves and their descendants. With this new flag, one can directly create as many partitions as necessary without ever using the v1 trick of turning off load balancing in specific cpusets to create partitions as a side effect. This new flag is owned by the parent and will cause the CPUs in the cpuset to be removed from the effective CPUs of its parent. This is implemented internally by adding a new subparts_cpus mask that holds the CPUs belonging to child partitions so that: subparts_cpus | effective_cpus = cpus_allowed subparts_cpus & effective_cpus = 0 This new flag can only be turned on in a cpuset if its parent is a partition root itself. The state of this flag cannot be changed if the cpuset has children. Once turned on, further changes to "cpuset.cpus" is allowed as long as there is at least one CPU left that can be granted from the parent and a child partition root cannot use up all the CPUs in the parent's effective_cpus. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Simply allocation and freeing of cpumasksWaiman Long
The previous commit introduces a new subparts_cpus mask into the cpuset data structure and a new tmpmasks structure. Managing the allocation and freeing of those cpumasks is becoming more complex. So a number of helper functions are added to simplify and streamline the management of those cpumasks. To make it simple, all the cpumasks are now pre-cleared on allocation. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Define data structures to support scheduling partitionWaiman Long
>From a cpuset point of view, a scheduling partition is a group of cpusets with their own set of exclusive CPUs that are not shared by other tasks outside the scheduling partition. In the legacy hierarchy, scheduling partitions are supported indirectly via the right use of the load balancing and the exclusive CPUs flag which is not intuitive and can be hard to use. To fully support the concept of scheduling partitions in the default hierarchy, we need to add some new field into the cpuset structure as well as a new tmpmasks structure that is used to pre-allocate cpumasks at the top level cpuset functions to avoid memory allocation in inner functions as memory allocation failure in those inner functions may cause a cpuset to have inconsistent states. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08cpuset: Enable cpuset controller in default hierarchyWaiman Long
Given the fact that thread mode had been merged into 4.14, it is now time to enable cpuset to be used in the default hierarchy (cgroup v2) as it is clearly threaded. The cpuset controller had experienced feature creep since its introduction more than a decade ago. Besides the core cpus and mems control files to limit cpus and memory nodes, there are a bunch of additional features that can be controlled from the userspace. Some of the features are of doubtful usefulness and may not be actively used. This patch enables cpuset controller in the default hierarchy with a minimal set of features, namely just the cpus and mems and their effective_* counterparts. We can certainly add more features to the default hierarchy in the future if there is a real user need for them later on. Alternatively, with the unified hiearachy, it may make more sense to move some of those additional cpuset features, if desired, to memory controller or may be to the cpu controller instead of staying with cpuset. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-06-15docs: Fix some broken referencesMauro Carvalho Chehab
As we move stuff around, some doc references are broken. Fix some of them via this script: ./scripts/documentation-file-ref-check --fix Manually checked if the produced result is valid, removing a few false-positives. Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-12treewide: kmalloc() -> kmalloc_array()Kees Cook
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-02-06kernel/cpuset: current_cpuset_is_being_rebound can be booleanYaowei Bai
Make current_cpuset_is_being_rebound return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-4-git-send-email-baiyaowei@cmss.chinamobile.com Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-27sched/isolation: Move isolcpus= handling to the housekeeping codeFrederic Weisbecker
We want to centralize the isolation features, to be done by the housekeeping subsystem and scheduler domain isolation is a significant part of it. No intended behaviour change, we just reuse the housekeeping cpumask and core code. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-11-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-12Merge 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: "Three fixes: - fix a suspend/resume cpusets bug - fix a !CONFIG_NUMA_BALANCING bug - fix a kerneldoc warning" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix nuisance kernel-doc warning sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs sched/fair: Fix wake_affine_llc() balancing rules
2017-09-07sched/cpuset/pm: Fix cpuset vs. suspend-resume bugsPeter Zijlstra
Cpusets vs. suspend-resume is _completely_ broken. And it got noticed because it now resulted in non-cpuset usage breaking too. On suspend cpuset_cpu_inactive() doesn't call into cpuset_update_active_cpus() because it doesn't want to move tasks about, there is no need, all tasks are frozen and won't run again until after we've resumed everything. But this means that when we finally do call into cpuset_update_active_cpus() after resuming the last frozen cpu in cpuset_cpu_active(), the top_cpuset will not have any difference with the cpu_active_mask and this it will not in fact do _anything_. So the cpuset configuration will not be restored. This was largely hidden because we would unconditionally create identity domains and mobile users would not in fact use cpusets much. And servers what do use cpusets tend to not suspend-resume much. An addition problem is that we'd not in fact wait for the cpuset work to finish before resuming the tasks, allowing spurious migrations outside of the specified domains. Fix the rebuild by introducing cpuset_force_rebuild() and fix the ordering with cpuset_wait_for_hotplug(). Reported-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: deb7aa308ea2 ("cpuset: reorganize CPU / memory hotplug handling") Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-06Merge branch 'for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Several notable changes this cycle: - Thread mode was merged. This will be used for cgroup2 support for CPU and possibly other controllers. Unfortunately, CPU controller cgroup2 support didn't make this pull request but most contentions have been resolved and the support is likely to be merged before the next merge window. - cgroup.stat now shows the number of descendant cgroups. - cpuset now can enable the easier-to-configure v2 behavior on v1 hierarchy" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cpuset: Allow v2 behavior in v1 cgroup cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup cgroup: remove unneeded checks cgroup: misc changes cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy cgroup: re-use the parent pointer in cgroup_destroy_locked() cgroup: add cgroup.stat interface with basic hierarchy stats cgroup: implement hierarchy limits cgroup: keep track of number of descent cgroups cgroup: add comment to cgroup_enable_threaded() cgroup: remove unnecessary empty check when enabling threaded mode cgroup: update debug controller to print out thread mode information cgroup: implement cgroup v2 thread support cgroup: implement CSS_TASK_ITER_THREADED cgroup: introduce cgroup->dom_cgrp and threaded css_set handling cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS cgroup: reorganize cgroup.procs / task write path cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets cgroup: distinguish local and children populated states cgroup: remove now unused list_head @pending in cgroup_apply_cftypes() ...
2017-09-06mm: replace TIF_MEMDIE checks by tsk_is_oom_victimMichal Hocko
TIF_MEMDIE is set only to the tasks whick were either directly selected by the OOM killer or passed through mark_oom_victim from the allocator path. tsk_is_oom_victim is more generic and allows to identify all tasks (threads) which share the mm with the oom victim. Please note that the freezer still needs to check TIF_MEMDIE because we cannot thaw tasks which do not participage in oom_victims counting otherwise a !TIF_MEMDIE task could interfere after oom_disbale returns. Link: http://lkml.kernel.org/r/20170810075019.28998-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-04Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: - Add 'cross-release' support to lockdep, which allows APIs like completions, where it's not the 'owner' who releases the lock, to be tracked. It's all activated automatically under CONFIG_PROVE_LOCKING=y. - Clean up (restructure) the x86 atomics op implementation to be more readable, in preparation of KASAN annotations. (Dmitry Vyukov) - Fix static keys (Paolo Bonzini) - Add killable versions of down_read() et al (Kirill Tkhai) - Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini) - Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra) - Remove smp_mb__before_spinlock() and convert its usages, introduce smp_mb__after_spinlock() (Peter Zijlstra) * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits) locking/lockdep/selftests: Fix mixed read-write ABBA tests sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK() acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures smp: Avoid using two cache lines for struct call_single_data locking/lockdep: Untangle xhlock history save/restore from task independence locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being futex: Remove duplicated code and fix undefined behaviour Documentation/locking/atomic: Finish the document... locking/lockdep: Fix workqueue crossrelease annotation workqueue/lockdep: 'Fix' flush_work() annotation locking/lockdep/selftests: Add mixed read-write ABBA tests mm, locking/barriers: Clarify tlb_flush_pending() barriers locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive locking/lockdep: Explicitly initialize wq_barrier::done::map locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING locking/refcounts, x86/asm: Implement fast refcount overflow protection locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease ...
2017-09-04Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - fix affine wakeups (Peter Zijlstra) - improve CPU onlining (and general bootup) scalability on systems with ridiculous number (thousands) of CPUs (Peter Zijlstra) - sched/numa updates (Rik van Riel) - sched/deadline updates (Byungchul Park) - sched/cpufreq enhancements and related cleanups (Viresh Kumar) - sched/debug enhancements (Xie XiuQi) - various fixes" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) sched/debug: Optimize sched_domain sysctl generation sched/topology: Avoid pointless rebuild sched/topology, cpuset: Avoid spurious/wrong domain rebuilds sched/topology: Improve comments sched/topology: Fix memory leak in __sdt_alloc() sched/completion: Document that reinit_completion() must be called after complete_all() sched/autogroup: Fix error reporting printk text in autogroup_create() sched/fair: Fix wake_affine() for !NUMA_BALANCING sched/debug: Intruduce task_state_to_char() helper function sched/debug: Show task state in /proc/sched_debug sched/debug: Use task_pid_nr_ns in /proc/$pid/sched sched/core: Remove unnecessary initialization init_idle_bootup_task() sched/deadline: Change return value of cpudl_find() sched/deadline: Make find_later_rq() choose a closer CPU in topology sched/numa: Scale scan period with tasks in group and shared/private sched/numa: Slow down scan rate if shared faults dominate sched/pelt: Fix false running accounting sched: Mark pick_next_task_dl() and build_sched_domain() as static sched/cpupri: Don't re-initialize 'struct cpupri' sched/deadline: Don't re-initialize 'struct cpudl' ...
2017-09-04Merge branch 'linus' into locking/core, to fix up conflictsIngo Molnar
Conflicts: mm/page_alloc.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29Merge branch 'for-4.13-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "A late but obvious fix for cgroup. I broke the 'cpuset.memory_pressure' file a long time ago (v4.4) by accidentally deleting its file index, which made it a duplicate of the 'cpuset.memory_migrate' file. Spotted and fixed by Waiman" * 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: Fix incorrect memory_pressure control file mapping
2017-08-25sched/topology, cpuset: Avoid spurious/wrong domain rebuildsPeter Zijlstra
When disabling cpuset.sched_load_balance we expect to be able to online CPUs without generating sched_domains. However this is currently completely broken. What happens is that we generate the sched_domains and then destroy them. This is because of the spurious 'default' domain build in cpuset_update_active_cpus(). That builds a single machine wide domain and then schedules a work to build the 'real' domains. The work then finds there are _no_ domains and destroys the lot again. Furthermore, if there actually were cpusets, building the machine wide domain is actively wrong, because it would allow tasks to 'escape' their cpuset. Also I don't think its needed, the scheduler really should respect the active mask. Reported-by: Ofer Levi(SW) <oferle@mellanox.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet.Gupta1@synopsys.com <Vineet.Gupta1@synopsys.com> Cc: rusty@rustcorp.com.au <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-24cpuset: Fix incorrect memory_pressure control file mappingWaiman Long
The memory_pressure control file was incorrectly set up without a private value (0, by default). As a result, this control file was treated like memory_migrate on read. By adding back the FILE_MEMORY_PRESSURE private value, the correct memory pressure value will be returned. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 7dbdb199d3bf ("cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLE") Cc: stable@vger.kernel.org # v4.4+
2017-08-18cpuset: Allow v2 behavior in v1 cgroupWaiman Long
Cpuset v2 has some useful behaviors that are not present in v1 because of backward compatibility concern. One of that is the restoration of the original cpu and memory node mask after a hot removal and addition event sequence. This patch makes the cpuset controller to check the CGRP_ROOT_CPUSET_V2_MODE flag and use the v2 behavior if it is set. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-08-10cpuset: Make nr_cpusets privatePaolo Bonzini
Any use of key->enabled (that is static_key_enabled and static_key_count) outside jump_label_lock should handle its own serialization. In the case of cpusets_enabled_key, the key is always incremented/decremented under cpuset_mutex, and hence the same rule applies to nr_cpusets. The rule *is* respected currently, but the mutex is static so nr_cpusets should be static too. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Zefan Li <lizefan@huawei.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/1501601046-35683-4-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-02cpuset: fix a deadlock due to incomplete patching of cpusets_enabled()Dima Zavin
In codepaths that use the begin/retry interface for reading mems_allowed_seq with irqs disabled, there exists a race condition that stalls the patch process after only modifying a subset of the static_branch call sites. This problem manifested itself as a deadlock in the slub allocator, inside get_any_partial. The loop reads mems_allowed_seq value (via read_mems_allowed_begin), performs the defrag operation, and then verifies the consistency of mem_allowed via the read_mems_allowed_retry and the cookie returned by xxx_begin. The issue here is that both begin and retry first check if cpusets are enabled via cpusets_enabled() static branch. This branch can be rewritted dynamically (via cpuset_inc) if a new cpuset is created. The x86 jump label code fully synchronizes across all CPUs for every entry it rewrites. If it rewrites only one of the callsites (specifically the one in read_mems_allowed_retry) and then waits for the smp_call_function(do_sync_core) to complete while a CPU is inside the begin/retry section with IRQs off and the mems_allowed value is changed, we can hang. This is because begin() will always return 0 (since it wasn't patched yet) while retry() will test the 0 against the actual value of the seq counter. The fix is to use two different static keys: one for begin (pre_enable_key) and one for retry (enable_key). In cpuset_inc(), we first bump the pre_enable key to ensure that cpuset_mems_allowed_begin() always return a valid seqcount if are enabling cpusets. Similarly, when disabling cpusets via cpuset_dec(), we first ensure that callers of cpuset_mems_allowed_retry() will start ignoring the seqcount value before we let cpuset_mems_allowed_begin() return 0. The relevant stack traces of the two stuck threads: CPU: 1 PID: 1415 Comm: mkdir Tainted: G L 4.9.36-00104-g540c51286237 #4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8817f9c28000 task.stack: ffffc9000ffa4000 RIP: smp_call_function_many+0x1f9/0x260 Call Trace: smp_call_function+0x3b/0x70 on_each_cpu+0x2f/0x90 text_poke_bp+0x87/0xd0 arch_jump_label_transform+0x93/0x100 __jump_label_update+0x77/0x90 jump_label_update+0xaa/0xc0 static_key_slow_inc+0x9e/0xb0 cpuset_css_online+0x70/0x2e0 online_css+0x2c/0xa0 cgroup_apply_control_enable+0x27f/0x3d0 cgroup_mkdir+0x2b7/0x420 kernfs_iop_mkdir+0x5a/0x80 vfs_mkdir+0xf6/0x1a0 SyS_mkdir+0xb7/0xe0 entry_SYSCALL_64_fastpath+0x18/0xad ... CPU: 2 PID: 1 Comm: init Tainted: G L 4.9.36-00104-g540c51286237 #4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8818087c0000 task.stack: ffffc90000030000 RIP: int3+0x39/0x70 Call Trace: <#DB> ? ___slab_alloc+0x28b/0x5a0 <EOE> ? copy_process.part.40+0xf7/0x1de0 __slab_alloc.isra.80+0x54/0x90 copy_process.part.40+0xf7/0x1de0 copy_process.part.40+0xf7/0x1de0 kmem_cache_alloc_node+0x8a/0x280 copy_process.part.40+0xf7/0x1de0 _do_fork+0xe7/0x6c0 _raw_spin_unlock_irq+0x2d/0x60 trace_hardirqs_on_caller+0x136/0x1d0 entry_SYSCALL_64_fastpath+0x5/0xad do_syscall_64+0x27/0x350 SyS_clone+0x19/0x20 do_syscall_64+0x60/0x350 entry_SYSCALL64_slow_path+0x25/0x25 Link: http://lkml.kernel.org/r/20170731040113.14197-1-dmitriyz@waymo.com Fixes: 46e700abc44c ("mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled") Signed-off-by: Dima Zavin <dmitriyz@waymo.com> Reported-by: Cliff Spradlin <cspradlin@waymo.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christopher Lameter <cl@linux.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-21cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCSTejun Heo
css_task_iter currently always walks all tasks. With the scheduled cgroup v2 thread support, the iterator would need to handle multiple types of iteration. As a preparation, add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS. If the flag is not specified, it walks all tasks as before. When asserted, the iterator only walks the group leaders. For now, the only user of the flag is cgroup v2 "cgroup.procs" file which no longer needs to skip non-leader tasks in cgroup_procs_next(). Note that cgroup v1 "cgroup.procs" can't use the group leader walk as v1 "cgroup.procs" doesn't mean "list all thread group leaders in the cgroup" but "list all thread group id's with any threads in the cgroup". While at it, update cgroup_procs_show() to use task_pid_vnr() instead of task_tgid_vnr(). As the iteration guarantees that the function only sees group leaders, this doesn't change the output and will allow sharing the function for thread iteration. Signed-off-by: Tejun Heo <tj@kernel.org>
2017-07-06mm, cpuset: always use seqlock when changing task's nodemaskVlastimil Babka
When updating task's mems_allowed and rebinding its mempolicy due to cpuset's mems being changed, we currently only take the seqlock for writing when either the task has a mempolicy, or the new mems has no intersection with the old mems. This should be enough to prevent a parallel allocation seeing no available nodes, but the optimization is IMHO unnecessary (cpuset updates should not be frequent), and we still potentially risk issues if the intersection of new and old nodes has limited amount of free/reclaimable memory. Let's just use the seqlock for all tasks. Link: http://lkml.kernel.org/r/20170517081140.30654-6-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Hugh Dickins <hughd@google.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06mm, mempolicy: simplify rebinding mempolicies when updating cpusetsVlastimil Babka
Commit c0ff7453bb5c ("cpuset,mm: fix no node to alloc memory when changing cpuset's mems") has introduced a two-step protocol when rebinding task's mempolicy due to cpuset update, in order to avoid a parallel allocation seeing an empty effective nodemask and failing. Later, commit cc9a6c877661 ("cpuset: mm: reduce large amounts of memory barrier related damage v3") introduced a seqlock protection and removed the synchronization point between the two update steps. At that point (or perhaps later), the two-step rebinding became unnecessary. Currently it only makes sure that the update first adds new nodes in step 1 and then removes nodes in step 2. Without memory barriers the effects are questionable, and even then this cannot prevent a parallel zonelist iteration checking the nodemask at each step to observe all nodes as unusable for allocation. We now fully rely on the seqlock to prevent premature OOMs and allocation failures. We can thus remove the two-step update parts and simplify the code. Link: http://lkml.kernel.org/r/20170517081140.30654-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Hugh Dickins <hughd@google.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-24cpuset: consider dying css as offlineTejun Heo
In most cases, a cgroup controller don't care about the liftimes of cgroups. For the controller, a css becomes online when ->css_online() is called on it and offline when ->css_offline() is called. However, cpuset is special in that the user interface it exposes cares whether certain cgroups exist or not. Combined with the RCU delay between cgroup removal and css offlining, this can lead to user visible behavior oddities where operations which should succeed after cgroup removals fail for some time period. The effects of cgroup removals are delayed when seen from userland. This patch adds css_is_dying() which tests whether offline is pending and updates is_cpuset_online() so that the function returns false also while offline is pending. This gets rid of the userland visible delays. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Daniel Jordan <daniel.m.jordan@oracle.com> Link: http://lkml.kernel.org/r/327ca1f5-7957-fbb9-9e5f-9ba149d40ba2@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
2017-04-11cpuset: Remove cpuset_update_active_cpus()'s parameter.Rakib Mullick
In cpuset_update_active_cpus(), cpu_online isn't used anymore. Remove it. Signed-off-by: Rakib Mullick<rakib.mullick@gmail.com> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-27cgroup: switch to BUG_ON()Nicholas Mc Guire
Use BUG_ON() rather than an explicit if followed by BUG() for improved readability and also consistency. Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-02sched/headers: Prepare to move the task_lock()/unlock() APIs to ↵Ingo Molnar
<linux/sched/task.h> But first update the code that uses these facilities with the new header. Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: 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>
2016-12-27cgroup: move cgroup files under kernel/cgroup/Tejun Heo
They're growing to be too many and planned to get split further. Move them under their own directory. kernel/cgroup.c -> kernel/cgroup/cgroup.c kernel/cgroup_freezer.c -> kernel/cgroup/freezer.c kernel/cgroup_pids.c -> kernel/cgroup/pids.c kernel/cpuset.c -> kernel/cgroup/cpuset.c Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>