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2015-08-06audit: implement audit by executableRichard Guy Briggs5-1/+92
This adds the ability audit the actions of a not-yet-running process. This patch implements the ability to filter on the executable path. Instead of just hard coding the ino and dev of the executable we care about at the moment the rule is inserted into the kernel, use the new audit_fsnotify infrastructure to manage this dynamically. This means that if the filename does not yet exist but the containing directory does, or if the inode in question is unlinked and creat'd (aka updated) the rule will just continue to work. If the containing directory is moved or deleted or the filesystem is unmounted, the rule is deleted automatically. A future enhancement would be to have the rule survive across directory disruptions. This is a heavily modified version of a patch originally submitted by Eric Paris with some ideas from Peter Moody. Cc: Peter Moody <[email protected]> Cc: Eric Paris <[email protected]> Signed-off-by: Richard Guy Briggs <[email protected]> [PM: minor whitespace clean to satisfy ./scripts/checkpatch] Signed-off-by: Paul Moore <[email protected]>
2015-08-06audit: clean simple fsnotify implementationRichard Guy Briggs4-2/+232
This is to be used to audit by executable path rules, but audit watches should be able to share this code eventually. At the moment the audit watch code is a lot more complex. That code only creates one fsnotify watch per parent directory. That 'audit_parent' in turn has a list of 'audit_watches' which contain the name, ino, dev of the specific object we care about. This just creates one fsnotify watch per object we care about. So if you watch 100 inodes in /etc this code will create 100 fsnotify watches on /etc. The audit_watch code will instead create 1 fsnotify watch on /etc (the audit_parent) and then 100 individual watches chained from that fsnotify mark. We should be able to convert the audit_watch code to do one fsnotify mark per watch and simplify things/remove a whole lot of code. After that conversion we should be able to convert the audit_fsnotify code to support that hierarchy if the optimization is necessary. Move the access to the entry for audit_match_signal() to the beginning of the audit_del_rule() function in case the entry found is the same one passed in. This will enable it to be used by audit_autoremove_mark_rule(), kill_rules() and audit_remove_parent_watches(). This is a heavily modified and merged version of two patches originally submitted by Eric Paris. Cc: Peter Moody <[email protected]> Cc: Eric Paris <[email protected]> Signed-off-by: Richard Guy Briggs <[email protected]> [PM: added a space after a declaration to keep ./scripts/checkpatch happy] Signed-off-by: Paul Moore <[email protected]>
2015-08-06audit: use macros for unset inode and device valuesRichard Guy Briggs3-8/+8
Clean up a number of places were casted magic numbers are used to represent unset inode and device numbers in preparation for the audit by executable path patch set. Signed-off-by: Richard Guy Briggs <[email protected]> [PM: enclosed the _UNSET macros in parentheses for ./scripts/checkpatch] Signed-off-by: Paul Moore <[email protected]>
2015-08-06tracing, perf: Implement BPF programs attached to uprobesWang Nan3-3/+8
By copying BPF related operation to uprobe processing path, this patch allow users attach BPF programs to uprobes like what they are already doing on kprobes. After this patch, users are allowed to use PERF_EVENT_IOC_SET_BPF on a uprobe perf event. Which make it possible to profile user space programs and kernel events together using BPF. Because of this patch, CONFIG_BPF_EVENTS should be selected by CONFIG_UPROBE_EVENT to ensure trace_call_bpf() is compiled even if KPROBE_EVENT is not set. Signed-off-by: Wang Nan <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Cc: Brendan Gregg <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: David Ahern <[email protected]> Cc: He Kuang <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kaixu Xia <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Zefan Li <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-08-05kernel, cpu: Remove bogus __ref annotationsMathias Krause1-8/+8
cpu_chain lost its __cpuinitdata annotation long ago in commit 5c113fbeed7a ("fix cpu_chain section mismatch..."). This and the global __cpuinit annotation drop in v3.11 vanished the need to mark all users, including transitive ones, with the __ref annotation. Just get rid of it to not wrongly hide section mismatches. Signed-off-by: Mathias Krause <[email protected]> Cc: Paul Gortmaker <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2015-08-05audit: make audit_del_rule() more robustRichard Guy Briggs1-6/+6
Move the access to the entry for audit_match_signal() to earlier in the function in case the entry found is the same one passed in. This will enable it to be used by audit_remove_mark_rule(). Signed-off-by: Richard Guy Briggs <[email protected]> [PM: tweaked subject line as it no longer made sense after multiple revs] Signed-off-by: Paul Moore <[email protected]>
2015-08-05cgroup: export cgrp_dfl_rootTejun Heo1-0/+1
While cgroup subsystems can't be modules, blkcg supports dynamically loadable policies which interact with cgroup core. Export cgrp_dfl_root so that cgroup_on_dfl() can be used in those modules. Signed-off-by: Tejun Heo <[email protected]> Acked-by: Li Zefan <[email protected]> Cc: Johannes Weiner <[email protected]>
2015-08-05cpu-hotplug: export cpu_hotplug_enable/cpu_hotplug_disableVitaly Kuznetsov1-1/+2
Hyper-V module needs to disable cpu hotplug (offlining) as there is no support from hypervisor side to reassign already opened event channels to a different CPU. Currently it is been done by altering smp_ops.cpu_disable but it is hackish. Signed-off-by: Vitaly Kuznetsov <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Signed-off-by: K. Y. Srinivasan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2015-08-05cpu-hotplug: convert cpu_hotplug_disabled to a counterVitaly Kuznetsov1-8/+13
As a prerequisite to exporting cpu_hotplug_enable/cpu_hotplug_disable functions to modules we need to convert cpu_hotplug_disabled to a counter to properly support disable -> disable -> enable call sequences. E.g. after Hyper-V vmbus module (which is supposed to be the first user of exported cpu_hotplug_enable/cpu_hotplug_disable) did cpu_hotplug_disable() hibernate path calls disable_nonboot_cpus() and if we hit an error in _cpu_down() enable_nonboot_cpus() will be called on the failure path (thus making cpu_hotplug_disabled = 0 and leaving cpu hotplug in 'enabled' state). Same problem is possible if more than 1 module use cpu_hotplug_disable/cpu_hotplug_enable on their load/unload paths. When one of these modules is been unloaded it is logical to leave cpu hotplug in 'disabled' state. To support the change we need to increse cpu_hotplug_disabled counter in disable_nonboot_cpus() unconditionally as all users of disable_nonboot_cpus() are supposed to do enable_nonboot_cpus() in case an error was returned. Signed-off-by: Vitaly Kuznetsov <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Signed-off-by: K. Y. Srinivasan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2015-08-05audit: fix uninitialized variable in audit_add_rule()Paul Moore1-1/+1
As reported by the 0-Day testing service: kernel/auditfilter.c: In function 'audit_rule_change': >> kernel/auditfilter.c:864:6: warning: 'err' may be used uninit... int err; Cc: Richard Guy Briggs <[email protected]> Signed-off-by: Paul Moore <[email protected]>
2015-08-04audit: eliminate unnecessary extra layer of watch parent referencesRichard Guy Briggs1-4/+2
The audit watch parent count was imbalanced, adding an unnecessary layer of watch parent references. Decrement the additional parent reference when a watch is reused, already having a reference to the parent. audit_find_parent() gets a reference to the parent, if the parent is already known. This additional parental reference is not needed if the watch is subsequently found by audit_add_to_parent(), and consumed if the watch does not already exist, so we need to put the parent if the watch is found, and do nothing if this new watch is added to the parent. If the parent wasn't already known, it is created with a refcount of 1 and added to the audit_watch_group, then incremented by one to be subsequently consumed by the newly created watch in audit_add_to_parent(). The rule points to the watch, not to the parent, so the rule's refcount gets bumped, not the parent's. See LKML, 2015-07-16 Signed-off-by: Richard Guy Briggs <[email protected]> Signed-off-by: Paul Moore <[email protected]>
2015-08-04audit: eliminate unnecessary extra layer of watch referencesRichard Guy Briggs2-16/+5
The audit watch count was imbalanced, adding an unnecessary layer of watch references. Only add the second reference when it is added to a parent. Signed-off-by: Richard Guy Briggs <[email protected]> Signed-off-by: Paul Moore <[email protected]>
2015-08-04workqueue: Make flush_workqueue() available again to non GPL modulesTim Gardner1-1/+1
Commit 37b1ef31a568fc02e53587620226e5f3c66454c8 ("workqueue: move flush_scheduled_work() to workqueue.h") moved the exported non GPL flush_scheduled_work() from a function to an inline wrapper. Unfortunately, it directly calls flush_workqueue() which is a GPL function. This has the effect of changing the licensing requirement for this function and makes it unavailable to non GPL modules. See commit ad7b1f841f8a54c6d61ff181451f55b68175e15a ("workqueue: Make schedule_work() available again to non GPL modules") for precedent. Signed-off-by: Tim Gardner <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
2015-08-04rcu,locking: Privatize smp_mb__after_unlock_lock()Paul E. McKenney1-0/+12
RCU is the only thing that uses smp_mb__after_unlock_lock(), and is likely the only thing that ever will use it, so this commit makes this macro private to RCU. Signed-off-by: Paul E. McKenney <[email protected]> Cc: Will Deacon <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: "[email protected]" <[email protected]>
2015-08-04Merge branches 'doc.2015.07.15a' and 'torture.2015.07.15a' into HEADPaul E. McKenney1-13/+27
doc.2015.07.15a: Documentation updates. torture.2015.07.15a: Torture-test updates.
2015-08-04Merge branches 'fixes.2015.07.22a' and 'initexp.2015.08.04a' into HEADPaul E. McKenney4-408/+401
fixes.2015.07.22a: Miscellaneous fixes. initexp.2015.08.04a: Initialization and expedited updates. (Single branch due to conflicts.)
2015-08-04rcu: Silence lockdep false positive for expedited grace periodsPaul E. McKenney2-2/+18
In a CONFIG_PREEMPT=y kernel, synchronize_rcu_expedited() acquires the ->exp_funnel_mutex in rcu_preempt_state, then invokes synchronize_sched_expedited, which acquires the ->exp_funnel_mutex in rcu_sched_state. There can be no deadlock because rcu_preempt_state ->exp_funnel_mutex acquisition always precedes that of rcu_sched_state. But lockdep does not know that, so it gives false-positive splats. This commit therefore associates a separate lock_class_key structure with the rcu_sched_state structure's ->exp_funnel_mutex, allowing lockdep to see the lock ordering, avoiding the false positives. Signed-off-by: Paul E. McKenney <[email protected]>
2015-08-04perf/x86/intel/pt: Do not force sync packets on every schedule-inAlexander Shishkin1-2/+0
Currently, the PT driver zeroes out the status register every time before starting the event. However, all the writable bits are already taken care of in pt_handle_status() function, except the new PacketByteCnt field, which in new versions of PT contains the number of packet bytes written since the last sync (PSB) packet. Zeroing it out before enabling PT forces a sync packet to be written. This means that, with the existing code, a sync packet (PSB and PSBEND, 18 bytes in total) will be generated every time a PT event is scheduled in. To avoid these unnecessary syncs and save a WRMSR in the fast path, this patch changes the default behavior to not clear PacketByteCnt field, so that the sync packets will be generated with the period specified as "psb_period" attribute config field. This has little impact on the trace data as the other packets that are normally sent within PSB+ (between PSB and PSBEND) have their own generation scenarios which do not depend on the sync packets. One exception where we do need to force PSB like this when tracing starts, so that the decoder has a clear sync point in the trace. For this purpose we aready have hw::itrace_started flag, which we are currently using to output PERF_RECORD_ITRACE_START. This patch moves setting itrace_started from perf core to the pmu::start, where it should still be 0 on the very first run. Signed-off-by: Alexander Shishkin <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/1438264104-16189-1-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <[email protected]>
2015-08-04perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safeAndy Lutomirski1-1/+1
Code on the kprobe blacklist doesn't want unexpected int3 exceptions. It probably doesn't want unexpected debug exceptions either. Be safe: disallow breakpoints in nokprobes code. On non-CONFIG_KPROBES kernels, there is no kprobe blacklist. In that case, disallow kernel breakpoints entirely. It will be particularly important to keep hw breakpoints out of the entry and NMI code once we move debug exceptions off the IST stack. Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/e14b152af99640448d895e3c2a8c2d5ee19a1325.1438312874.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2015-08-04perf: Fix fasync handling on inherited eventsPeter Zijlstra1-2/+10
Vince reported that the fasync signal stuff doesn't work proper for inherited events. So fix that. Installing fasync allocates memory and sets filp->f_flags |= FASYNC, which upon the demise of the file descriptor ensures the allocation is freed and state is updated. Now for perf, we can have the events stick around for a while after the original FD is dead because of references from child events. So we cannot copy the fasync pointer around. We can however consistently use the parent's fasync, as that will be updated. Reported-and-Tested-by: Vince Weaver <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: <[email protected]> Cc: Arnaldo Carvalho deMelo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/1434011521.1495.71.camel@twins Signed-off-by: Ingo Molnar <[email protected]>
2015-08-04sched: Remove finish_arch_switch()Peter Zijlstra2-4/+0
One less arch hook.. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03cgroup: fix idr_preload usageVladimir Davydov1-4/+4
It does not make much sense to call idr_preload with the same gfp mask as the following idr_alloc, but this is what we do in cgroup_idr_alloc. This patch fixes the idr_preload usage by making cgroup_idr_alloc call idr_alloc w/o __GFP_WAIT. Since it is now safe to call cgroup_idr_alloc with GFP_KERNEL, the patch also fixes all its callers appropriately. Signed-off-by: Vladimir Davydov <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
2015-08-03sched/fair: Clean up load average referencesYuyang Du1-15/+29
For cfs_rq, we have load.weight, runnable_load_avg, and load_avg. Clean up how they are used: - First, as group sched_entity already largely uses load_avg, we now expand to use load_avg in all cases. - Second, for CPU-wide load balancing, we choose to use runnable_load_avg in all cases, which is the same as before this series. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Provide runnable_load_avg back to cfs_rqYuyang Du3-10/+49
The cfs_rq's load_avg is composed of runnable_load_avg and blocked_load_avg. Before this series, sometimes the runnable_load_avg is used, and sometimes the load_avg is used. Completely replacing all uses of runnable_load_avg with load_avg may be too big a leap, i.e., the blocked_load_avg is concerned to result in overrated load. Therefore, we get runnable_load_avg back. The new cfs_rq's runnable_load_avg is improved to be updated with all of the runnable sched_eneities at the same time, so the one sched_entity updated and the others stale problem is solved. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Remove task and group entity load when they are deadYuyang Du1-1/+10
When task exits or group is destroyed, the entity's load should be removed from its parent cfs_rq's load. Otherwise, it will take time for the parent cfs_rq to decay the dead entity's load to 0, which is not desired. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Init cfs_rq's sched_entity load averageYuyang Du3-7/+8
The runnable load and utilization averages of cfs_rq's sched_entity were not initiated. Like done to a task, give new cfs_rq' sched_entity start values to heavy its load in infant time. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Implement update_blocked_averages() for CONFIG_FAIR_GROUP_SCHED=nVincent Guittot1-0/+8
The load and the utilization of idle CPUs must be updated periodically in order to decay the blocked part. If CONFIG_FAIR_GROUP_SCHED is not set, the load and util of idle cpus are not decayed and stay at the values set before becoming idle. Signed-off-by: Vincent Guittot <[email protected]> Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] [ Fixed up the SOB chain. ] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Rewrite runnable load and utilization average trackingYuyang Du4-471/+231
The idea of runnable load average (let runnable time contribute to weight) was proposed by Paul Turner and Ben Segall, and it is still followed by this rewrite. This rewrite aims to solve the following issues: 1. cfs_rq's load average (namely runnable_load_avg and blocked_load_avg) is updated at the granularity of an entity at a time, which results in the cfs_rq's load average is stale or partially updated: at any time, only one entity is up to date, all other entities are effectively lagging behind. This is undesirable. To illustrate, if we have n runnable entities in the cfs_rq, as time elapses, they certainly become outdated: t0: cfs_rq { e1_old, e2_old, ..., en_old } and when we update: t1: update e1, then we have cfs_rq { e1_new, e2_old, ..., en_old } t2: update e2, then we have cfs_rq { e1_old, e2_new, ..., en_old } ... We solve this by combining all runnable entities' load averages together in cfs_rq's avg, and update the cfs_rq's avg as a whole. This is based on the fact that if we regard the update as a function, then: w * update(e) = update(w * e) and update(e1) + update(e2) = update(e1 + e2), then w1 * update(e1) + w2 * update(e2) = update(w1 * e1 + w2 * e2) therefore, by this rewrite, we have an entirely updated cfs_rq at the time we update it: t1: update cfs_rq { e1_new, e2_new, ..., en_new } t2: update cfs_rq { e1_new, e2_new, ..., en_new } ... 2. cfs_rq's load average is different between top rq->cfs_rq and other task_group's per CPU cfs_rqs in whether or not blocked_load_average contributes to the load. The basic idea behind runnable load average (the same for utilization) is that the blocked state is taken into account as opposed to only accounting for the currently runnable state. Therefore, the average should include both the runnable/running and blocked load averages. This rewrite does that. In addition, we also combine runnable/running and blocked averages of all entities into the cfs_rq's average, and update it together at once. This is based on the fact that: update(runnable) + update(blocked) = update(runnable + blocked) This significantly reduces the code as we don't need to separately maintain/update runnable/running load and blocked load. 3. How task_group entities' share is calculated is complex and imprecise. We reduce the complexity in this rewrite to allow a very simple rule: the task_group's load_avg is aggregated from its per CPU cfs_rqs's load_avgs. Then group entity's weight is simply proportional to its own cfs_rq's load_avg / task_group's load_avg. To illustrate, if a task_group has { cfs_rq1, cfs_rq2, ..., cfs_rqn }, then, task_group_avg = cfs_rq1_avg + cfs_rq2_avg + ... + cfs_rqn_avg, then cfs_rqx's entity's share = cfs_rqx_avg / task_group_avg * task_group's share To sum up, this rewrite in principle is equivalent to the current one, but fixes the issues described above. Turns out, it significantly reduces the code complexity and hence increases clarity and efficiency. In addition, the new averages are more smooth/continuous (no spurious spikes and valleys) and updated more consistently and quickly to reflect the load dynamics. As a result, we have less load tracking overhead, better performance, and especially better power efficiency due to more balanced load. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Remove rq's runnable avgYuyang Du3-29/+5
The current rq->avg is not used at all since its merge into the kernel, and the code is in the scheduler's hot path, so remove it. Tested-by: Dietmar Eggemann <[email protected]> Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Dietmar Eggemann <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03stop_machine: Remove cpu_stop_work's from list in cpu_stop_park()Oleg Nesterov1-2/+4
cpu_stop_park() does cpu_stop_signal_done() but leaves the work on stopper->works. The owner of this work can free/reuse this memory right after that and corrupt the list, so if this CPU becomes online again cpu_stopper_thread() will crash. Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03stop_machine: Use 'cpu_stop_fn_t' where possibleOleg Nesterov1-4/+4
Cosmetic, but 'cpu_stop_fn_t' actually makes the code more readable and it doesn't break cscope. And most of the declarations already use it. Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03stop_machine: Unexport __stop_machine()Oleg Nesterov2-2/+2
The only caller outside of stop_machine.c is _cpu_down(), it can use stop_machine(). get_online_cpus() is fine under cpu_hotplug_begin(). Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03stop_machine: Don't do for_each_cpu() twice in queue_stop_cpus_work()Oleg Nesterov1-10/+7
queue_stop_cpus_work() can do everything in one for_each_cpu() loop. Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03stop_machine: Move 'cpu_stopper_task' and 'stop_cpus_work' into 'struct ↵Oleg Nesterov1-8/+9
cpu_stopper' Multpiple DEFINE_PER_CPU's do not make sense, move all the per-cpu variables into 'struct cpu_stopper'. Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/preempt: Fix cond_resched_lock() and cond_resched_softirq()Konstantin Khlebnikov1-3/+3
These functions check should_resched() before unlocking spinlock/bh-enable: preempt_count always non-zero => should_resched() always returns false. cond_resched_lock() worked iff spin_needbreak is set. This patch adds argument "preempt_offset" to should_resched(). preempt_count offset constants for that: PREEMPT_DISABLE_OFFSET - offset after preempt_disable() PREEMPT_LOCK_OFFSET - offset after spin_lock() SOFTIRQ_DISABLE_OFFSET - offset after local_bh_distable() SOFTIRQ_LOCK_OFFSET - offset after spin_lock_bh() Signed-off-by: Konstantin Khlebnikov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Alexander Graf <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: David Vrabel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: bdb438065890 ("sched: Extract the basic add/sub preempt_count modifiers") Link: http://lkml.kernel.org/r/20150715095204.12246.98268.stgit@buzz Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Beef up wake_wide()Mike Galbraith1-34/+33
Josef Bacik reported that Facebook sees better performance with their 1:N load (1 dispatch/node, N workers/node) when carrying an old patch to try very hard to wake to an idle CPU. While looking at wake_wide(), I noticed that it doesn't pay attention to the wakeup of a many partner waker, returning 1 only when waking one of its many partners. Correct that, letting explicit domain flags override the heuristic. While at it, adjust task_struct bits, we don't need a 64-bit counter. Tested-by: Josef Bacik <[email protected]> Signed-off-by: Mike Galbraith <[email protected]> [ Tidy things up. ] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: kernel-team<[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched: Introduce the 'trace_sched_waking' tracepointPeter Zijlstra3-5/+9
Mathieu reported that since 317f394160e9 ("sched: Move the second half of ttwu() to the remote cpu") trace_sched_wakeup() can happen out of context of the waker. This is a problem when you want to analyse wakeup paths because it is now very hard to correlate the wakeup event to whoever issued the wakeup. OTOH trace_sched_wakeup() is issued at the point where we set p->state = TASK_RUNNING, which is right were we hand the task off to the scheduler, so this is an important point when looking at scheduling behaviour, up to here its been the wakeup path everything hereafter is due to scheduler policy. To bridge this gap, introduce a second tracepoint: trace_sched_waking. It is guaranteed to be called in the waker context. Reported-by: Mathieu Desnoyers <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Francis Giraldeau <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/cputime: Guarantee stime + utime == rtimePeter Zijlstra2-44/+64
While the current code guarantees monotonicity for stime and utime independently of one another, it does not guarantee that the sum of both is equal to the total time we started out with. This confuses things (and peoples) who look at this sum, like top, and will report >100% usage followed by a matching period of 0%. Rework the code to provide both individual monotonicity and a coherent sum. Suggested-by: Fredrik Markstrom <[email protected]> Reported-by: Fredrik Markstrom <[email protected]> Tested-by: Fredrik Markstrom <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Stanislaw Gruszka <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched, sysctl: Delete an unnecessary check before unregister_sysctl_table()Markus Elfring1-2/+1
The unregister_sysctl_table() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/deadline: Remove a redundant condition from task_woken_dl()Xunlei Pang1-1/+0
'p' has been already queued at this point, so "!task_running(rq, p)" and "p->nr_cpus_allowed > 1" imply that "has_pushable_dl_tasks(rq)" is true, so it can be removed. Signed-off-by: Xunlei Pang <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Steven Rostedt <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/rt: Remove a redundant condition from task_woken_rt()Xunlei Pang1-1/+0
'p' has been already queued at this point, so "!task_running(rq, p)" and "p->nr_cpus_allowed > 1" imply that "has_pushable_tasks(rq)" is true, so it can be removed. Signed-off-by: Xunlei Pang <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Steven Rostedt <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03sched/fair: Avoid pulling all tasks in idle balancingYuyang Du1-0/+7
In idle balancing where a CPU going idle pulls tasks from another CPU, a livelock may happen if the CPU pulls all tasks from another, makes it idle, and this iterates. So just avoid this. Reported-by: Rabin Vincent <[email protected]> Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Ben Segall <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Morten Rasmussen <[email protected]> Cc: Paul Turner <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03locking/static_keys: Add selftestPeter Zijlstra1-1/+38
Add a little selftest that validates all combinations. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03locking/static_keys: Add a new static_key interfacePeter Zijlstra1-7/+30
There are various problems and short-comings with the current static_key interface: - static_key_{true,false}() read like a branch depending on the key value, instead of the actual likely/unlikely branch depending on init value. - static_key_{true,false}() are, as stated above, tied to the static_key init values STATIC_KEY_INIT_{TRUE,FALSE}. - we're limited to the 2 (out of 4) possible options that compile to a default NOP because that's what our arch_static_branch() assembly emits. So provide a new static_key interface: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); Which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. This means adding a second arch_static_branch_jump() assembly helper which emits a JMP per default. In order to determine the right instruction for the right state, encode the branch type in the LSB of jump_entry::key. This is the final step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") ... but it also allows new static key combinations that will give us performance enhancements in the subsequent patches. Tested-by: Rabin Vincent <[email protected]> # arm Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Michael Ellerman <[email protected]> # ppc Acked-by: Heiko Carstens <[email protected]> # s390 Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03locking/static_keys: Rework update logicPeter Zijlstra1-50/+38
Instead of spreading the branch_default logic all over the place, concentrate it into the one jump_label_type() function. This does mean we need to actually increment/decrement the enabled count _before_ calling the update path, otherwise jump_label_type() will not see the right state. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03locking/static_keys: Add static_key_{en,dis}able() helpersPeter Zijlstra1-4/+2
Add two helpers to make it easier to treat the refcount as boolean. Suggested-by: Jason Baron <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03jump_label: Add jump_entry_key() helperPeter Zijlstra1-4/+9
Avoid some casting with a helper, also prepares the way for overloading the LSB of jump_entry::key. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03jump_label, locking/static_keys: Rename JUMP_LABEL_TYPE_* and related ↵Peter Zijlstra1-9/+16
helpers to the static_key* pattern Rename the JUMP_LABEL_TYPE_* macros to be JUMP_TYPE_* and move the inline helpers into kernel/jump_label.c, since that's the only place they're ever used. Also rename the helpers where it's all about static keys. This is the second step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}Peter Zijlstra1-9/+9
Since we've already stepped away from ENABLE is a JMP and DISABLE is a NOP with the branch_default bits, and are going to make it even worse, rename it to make it all clearer. This way we don't mix multiple levels of logic attributes, but have a plain 'physical' name for what the current instruction patching status of a jump label is. This is a first step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] [ Beefed up the changelog. ] Signed-off-by: Ingo Molnar <[email protected]>
2015-08-03Merge branch 'x86/asm' into locking/coreIngo Molnar2-0/+3
Upcoming changes to static keys is interacting/conflicting with the following pending TSC commits in tip:x86/asm: 4ea1636b04db x86/asm/tsc: Rename native_read_tsc() to rdtsc() ... So merge it into the locking tree to have a smoother resolution. Signed-off-by: Ingo Molnar <[email protected]>