When uclamp_max is being used, the util of the task could be higher than
the spare capacity of the CPU, but due to uclamp_max value we force-fit
it there.
The way the condition for checking for max_spare_cap in
find_energy_efficient_cpu() was constructed; it ignored any CPU that has
its spare_cap less than or _equal_ to max_spare_cap. Since we initialize
max_spare_cap to 0; this lead to never setting max_spare_cap_cpu and
hence ending up never performing compute_energy() for this cluster and
missing an opportunity for a better energy efficient placement to honour
uclamp_max setting.
max_spare_cap = 0;
cpu_cap = capacity_of(cpu) - cpu_util(p); // 0 if cpu_util(p) is high
...
util_fits_cpu(...); // will return true if uclamp_max forces it to fit
...
// this logic will fail to update max_spare_cap_cpu if cpu_cap is 0
if (cpu_cap > max_spare_cap) {
max_spare_cap = cpu_cap;
max_spare_cap_cpu = cpu;
}
prev_spare_cap suffers from a similar problem.
Fix the logic by converting the variables into long and treating -1
value as 'not populated' instead of 0 which is a viable and correct
spare capacity value. We need to be careful signed comparison is used
when comparing with cpu_cap in one of the conditions.
Fixes: 1d42509e47 ("sched/fair: Make EAS wakeup placement consider uclamp restrictions")
Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230916232955.2099394-2-qyousef@layalina.io
dl_rq->dl_nr_migratory is increased whenever a DL entity is enqueued and it has
nr_cpus_allowed > 1. Unlike the pushable_dl_tasks tree, dl_rq->dl_nr_migratory
includes a dl_rq's current task. This means a dl_rq can have a migratable
current, N non-migratable queued tasks, and be flagged as overloaded and have
its CPU set in the dlo_mask, despite having an empty pushable_tasks tree.
Make an dl_rq's overload logic be driven by {enqueue,dequeue}_pushable_dl_task(),
in other words make DL RQs only be flagged as overloaded if they have at
least one runnable-but-not-current migratable task.
o push_dl_task() is unaffected, as it is a no-op if there are no pushable
tasks.
o pull_dl_task() now no longer scans runqueues whose sole migratable task is
their current one, which it can't do anything about anyway.
It may also now pull tasks to a DL RQ with dl_nr_running > 1 if only its
current task is migratable.
Since dl_rq->dl_nr_migratory becomes unused, remove it.
RT had the exact same mechanism (rt_rq->rt_nr_migratory) which was dropped
in favour of relying on rt_rq->pushable_tasks, see:
612f769edd ("sched/rt: Make rt_rq->pushable_tasks updates drive rto_mask")
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20230928150251.463109-1-vschneid@redhat.com
Sebastian noted that the rto_push_work IRQ work can be queued for a CPU
that has an empty pushable_tasks list, which means nothing useful will be
done in the IPI other than queue the work for the next CPU on the rto_mask.
rto_push_irq_work_func() only operates on tasks in the pushable_tasks list,
but the conditions for that irq_work to be queued (and for a CPU to be
added to the rto_mask) rely on rq_rt->nr_migratory instead.
nr_migratory is increased whenever an RT task entity is enqueued and it has
nr_cpus_allowed > 1. Unlike the pushable_tasks list, nr_migratory includes a
rt_rq's current task. This means a rt_rq can have a migratible current, N
non-migratible queued tasks, and be flagged as overloaded / have its CPU
set in the rto_mask, despite having an empty pushable_tasks list.
Make an rt_rq's overload logic be driven by {enqueue,dequeue}_pushable_task().
Since rt_rq->{rt_nr_migratory,rt_nr_total} become unused, remove them.
Note that the case where the current task is pushed away to make way for a
migration-disabled task remains unchanged: the migration-disabled task has
to be in the pushable_tasks list in the first place, which means it has
nr_cpus_allowed > 1.
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20230811112044.3302588-1-vschneid@redhat.com
Simplify the conditional logic for checking worker flags
by splitting the original compound `if` statement into
separate `if` and `else if` clauses.
This modification not only retains the previous functionality,
but also reduces a single `if` check, improving code clarity
and potentially enhancing performance.
Signed-off-by: Wang Jinchao <wangjinchao@xfusion.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/ZOIMvURE99ZRAYEj@fedora
We've observed the following warning being hit in
distribute_cfs_runtime():
SCHED_WARN_ON(cfs_rq->runtime_remaining > 0)
We have the following race:
- CPU 0: running bandwidth distribution (distribute_cfs_runtime).
Inspects the local cfs_rq and makes its runtime_remaining positive.
However, we defer unthrottling the local cfs_rq until after
considering all remote cfs_rq's.
- CPU 1: starts running bandwidth distribution from the slack timer. When
it finds the cfs_rq for CPU 0 on the throttled list, it observers the
that the cfs_rq is throttled, yet is not on the CSD list, and has a
positive runtime_remaining, thus triggering the warning in
distribute_cfs_runtime.
To fix this, we can rework the local unthrottling logic to put the local
cfs_rq on a local list, so that any future bandwidth distributions will
realize that the cfs_rq is about to be unthrottled.
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230922230535.296350-2-joshdon@google.com
The list_head counterpart of list_for_each_entry_reverse() was missing,
add it to complete the list handling APIs in <linux/list.h>.
[ This new API is also relied on by a WIP scheduler patch, so this
variant is not a theoretical possibility only. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Except on x86, preempt_count is always accessed with READ_ONCE().
Repeated invocations in macros like irq_count() produce repeated loads.
These redundant instructions appear in various fast paths. In the one
shown below, for example, irq_count() is evaluated during kernel entry
if !tick_nohz_full_cpu(smp_processor_id()).
0001ed0a <irq_enter_rcu>:
1ed0a: 4e56 0000 linkw %fp,#0
1ed0e: 200f movel %sp,%d0
1ed10: 0280 ffff e000 andil #-8192,%d0
1ed16: 2040 moveal %d0,%a0
1ed18: 2028 0008 movel %a0@(8),%d0
1ed1c: 0680 0001 0000 addil #65536,%d0
1ed22: 2140 0008 movel %d0,%a0@(8)
1ed26: 082a 0001 000f btst #1,%a2@(15)
1ed2c: 670c beqs 1ed3a <irq_enter_rcu+0x30>
1ed2e: 2028 0008 movel %a0@(8),%d0
1ed32: 2028 0008 movel %a0@(8),%d0
1ed36: 2028 0008 movel %a0@(8),%d0
1ed3a: 4e5e unlk %fp
1ed3c: 4e75 rts
This patch doesn't prevent the pointless btst and beqs instructions
above, but it does eliminate 2 of the 3 pointless move instructions
here and elsewhere.
On x86, preempt_count is per-cpu data and the problem does not arise
presumably because the compiler is free to optimize more effectively.
This patch was tested on m68k and x86. I was expecting no changes
to object code for x86 and mostly that's what I saw. However, there
were a few places where code generation was perturbed for some reason.
The performance issue addressed here is minor on uniprocessor m68k. I
got a 0.01% improvement from this patch for a simple "find /sys -false"
benchmark. For architectures and workloads susceptible to cache line bounce
the improvement is expected to be larger. The only SMP architecture I have
is x86, and as x86 unaffected I have not done any further measurements.
Fixes: 15115830c8 ("preempt: Cleanup the macro maze a bit")
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/0a403120a682a525e6db2d81d1a3ffcc137c3742.1694756831.git.fthain@linux-m68k.org
The name is a bit opaque - make it clear that this is about wakeup
preemption.
Also rename the ->check_preempt_curr() methods similarly.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Other scheduling classes already postfix their similar methods
with the class name.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
When using sysbench to benchmark Postgres in a single docker instance
with sysbench's nr_threads set to nr_cpu, it is observed there are times
update_cfs_group() and update_load_avg() shows noticeable overhead on
a 2sockets/112core/224cpu Intel Sapphire Rapids(SPR):
13.75% 13.74% [kernel.vmlinux] [k] update_cfs_group
10.63% 10.04% [kernel.vmlinux] [k] update_load_avg
Annotate shows the cycles are mostly spent on accessing tg->load_avg
with update_load_avg() being the write side and update_cfs_group() being
the read side. tg->load_avg is per task group and when different tasks
of the same taskgroup running on different CPUs frequently access
tg->load_avg, it can be heavily contended.
E.g. when running postgres_sysbench on a 2sockets/112cores/224cpus Intel
Sappire Rapids, during a 5s window, the wakeup number is 14millions and
migration number is 11millions and with each migration, the task's load
will transfer from src cfs_rq to target cfs_rq and each change involves
an update to tg->load_avg. Since the workload can trigger as many wakeups
and migrations, the access(both read and write) to tg->load_avg can be
unbound. As a result, the two mentioned functions showed noticeable
overhead. With netperf/nr_client=nr_cpu/UDP_RR, the problem is worse:
during a 5s window, wakeup number is 21millions and migration number is
14millions; update_cfs_group() costs ~25% and update_load_avg() costs ~16%.
Reduce the overhead by limiting updates to tg->load_avg to at most once
per ms. The update frequency is a tradeoff between tracking accuracy and
overhead. 1ms is chosen because PELT window is roughly 1ms and it
delivered good results for the tests that I've done. After this change,
the cost of accessing tg->load_avg is greatly reduced and performance
improved. Detailed test results below.
==============================
postgres_sysbench on SPR:
25%
base: 42382±19.8%
patch: 50174±9.5% (noise)
50%
base: 67626±1.3%
patch: 67365±3.1% (noise)
75%
base: 100216±1.2%
patch: 112470±0.1% +12.2%
100%
base: 93671±0.4%
patch: 113563±0.2% +21.2%
==============================
hackbench on ICL:
group=1
base: 114912±5.2%
patch: 117857±2.5% (noise)
group=4
base: 359902±1.6%
patch: 361685±2.7% (noise)
group=8
base: 461070±0.8%
patch: 491713±0.3% +6.6%
group=16
base: 309032±5.0%
patch: 378337±1.3% +22.4%
=============================
hackbench on SPR:
group=1
base: 100768±2.9%
patch: 103134±2.9% (noise)
group=4
base: 413830±12.5%
patch: 378660±16.6% (noise)
group=8
base: 436124±0.6%
patch: 490787±3.2% +12.5%
group=16
base: 457730±3.2%
patch: 680452±1.3% +48.8%
============================
netperf/udp_rr on ICL
25%
base: 114413±0.1%
patch: 115111±0.0% +0.6%
50%
base: 86803±0.5%
patch: 86611±0.0% (noise)
75%
base: 35959±5.3%
patch: 49801±0.6% +38.5%
100%
base: 61951±6.4%
patch: 70224±0.8% +13.4%
===========================
netperf/udp_rr on SPR
25%
base: 104954±1.3%
patch: 107312±2.8% (noise)
50%
base: 55394±4.6%
patch: 54940±7.4% (noise)
75%
base: 13779±3.1%
patch: 36105±1.1% +162%
100%
base: 9703±3.7%
patch: 28011±0.2% +189%
==============================================
netperf/tcp_stream on ICL (all in noise range)
25%
base: 43092±0.1%
patch: 42891±0.5%
50%
base: 19278±14.9%
patch: 22369±7.2%
75%
base: 16822±3.0%
patch: 17086±2.3%
100%
base: 18216±0.6%
patch: 18078±2.9%
===============================================
netperf/tcp_stream on SPR (all in noise range)
25%
base: 34491±0.3%
patch: 34886±0.5%
50%
base: 19278±14.9%
patch: 22369±7.2%
75%
base: 16822±3.0%
patch: 17086±2.3%
100%
base: 18216±0.6%
patch: 18078±2.9%
Reported-by: Nitin Tekchandani <nitin.tekchandani@intel.com>
Suggested-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: David Vernet <void@manifault.com>
Tested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tested-by: Swapnil Sapkal <Swapnil.Sapkal@amd.com>
Link: https://lkml.kernel.org/r/20230912065808.2530-2-aaron.lu@intel.com
After commit f5d39b0208 ("freezer,sched: Rewrite core freezer logic"),
tasks that transition directly from TASK_FREEZABLE to TASK_FROZEN are
always woken up on the thaw path. Prior to that commit, tasks could ask
freezer to consider them "frozen enough" via freezer_do_not_count(). The
commit replaced freezer_do_not_count() with a TASK_FREEZABLE state which
allows freezer to immediately mark the task as TASK_FROZEN without
waking up the task. This is efficient for the suspend path, but on the
thaw path, the task is always woken up even if the task didn't need to
wake up and goes back to its TASK_(UN)INTERRUPTIBLE state. Although
these tasks are capable of handling of the wakeup, we can observe a
power/perf impact from the extra wakeup.
We observed on Android many tasks wait in the TASK_FREEZABLE state
(particularly due to many of them being binder clients). We observed
nearly 4x the number of tasks and a corresponding linear increase in
latency and power consumption when thawing the system. The latency
increased from ~15ms to ~50ms.
Avoid the spurious wakeups by saving the state of TASK_FREEZABLE tasks.
If the task was running before entering TASK_FROZEN state
(__refrigerator()) or if the task received a wake up for the saved
state, then the task is woken on thaw. saved_state from PREEMPT_RT locks
can be re-used because freezer would not stomp on the rtlock wait flow:
TASK_RTLOCK_WAIT isn't considered freezable.
Reported-by: Prakash Viswalingam <quic_prakashv@quicinc.com>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for freezer to also use saved_state, remove the
CONFIG_PREEMPT_RT compilation guard around saved_state.
On the arm64 platform I tested which did not have CONFIG_PREEMPT_RT,
there was no statistically significant deviation by applying this patch.
Test methodology:
perf bench sched message -g 40 -l 40
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched_numa_find_nth_cpu() doesn't handle NUMA_NO_NODE properly, and
may crash kernel if passed with it. On the other hand, the only user
of sched_numa_find_nth_cpu() has to check NUMA_NO_NODE case explicitly.
It would be easier for users if this logic will get moved into
sched_numa_find_nth_cpu().
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20230819141239.287290-6-yury.norov@gmail.com
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull drm ci scripts from Dave Airlie:
"This is a bunch of ci integration for the freedesktop gitlab instance
where we currently do upstream userspace testing on diverse sets of
GPU hardware. From my perspective I think it's an experiment worth
going with and seeing how the benefits/noise playout keeping these
files useful.
Ideally I'd like to get this so we can do pre-merge testing on PRs
eventually.
Below is some info from danvet on why we've ended up making the
decision and how we can roll it back if we decide it was a bad plan.
Why in upstream?
- like documentation, testcases, tools CI integration is one of these
things where you can waste endless amounts of time if you
accidentally have a version that doesn't match your source code
- but also like the above, there's a balance, this is the initial cut
of what we think makes sense to keep in sync vs out-of-tree,
probably needs adjustment
- gitlab supports out-of-repo gitlab integration and that's what's
been used for the kernel in drm, but it results in per-driver
fragmentation and lots of duplicated effort. the simple act of
smashing an arbitrary winner into a topic branch already started
surfacing patches on dri-devel and sparking good cross driver team
discussions
Why gitlab?
- it's not any more shit than any of the other CI
- drm userspace uses it extensively for everything in userspace, we
have a lot of people and experience with this, including
integration of hw testing labs
- media userspace like gstreamer is also on gitlab.fd.o, and there's
discussion to extend this to the media subsystem in some fashion
Can this be shared?
- there's definitely a pile of code that could move to scripts/ if
other subsystem adopt ci integration in upstream kernel git. other
bits are more drm/gpu specific like the igt-gpu-tests/tools
integration
- docker images can be run locally or in other CI runners
Will we regret this?
- it's all in one directory, intentionally, for easy deletion
- probably 1-2 years in upstream to see whether this is worth it or a
Big Mistake. that's roughly what it took to _really_ roll out solid
CI in the bigger userspace projects we have on gitlab.fd.o like
mesa3d"
* tag 'topic/drm-ci-2023-08-31-1' of git://anongit.freedesktop.org/drm/drm:
drm: ci: docs: fix build warning - add missing escape
drm: Add initial ci/ subdirectory
Pull x86 fixes from Ingo Molnar:
"Fix preemption delays in the SGX code, remove unnecessarily
UAPI-exported code, fix a ld.lld linker (in)compatibility quirk and
make the x86 SMP init code a bit more conservative to fix kexec()
lockups"
* tag 'x86-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sgx: Break up long non-preemptible delays in sgx_vepc_release()
x86: Remove the arch_calc_vm_prot_bits() macro from the UAPI
x86/build: Fix linker fill bytes quirk/incompatibility for ld.lld
x86/smp: Don't send INIT to non-present and non-booted CPUs
Pull x86 perf event fix from Ingo Molnar:
"Work around a firmware bug in the uncore PMU driver, affecting certain
Intel systems"
* tag 'perf-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/uncore: Correct the number of CHAs on EMR
Pull perf tools updates from Arnaldo Carvalho de Melo:
"perf tools maintainership:
- Add git information for perf-tools and perf-tools-next trees and
branches to the MAINTAINERS file. That is where development now
takes place and myself and Namhyung Kim have write access, more
people to come as we emulate other maintainer groups.
perf record:
- Record kernel data maps when 'perf record --data' is used, so that
global variables can be resolved and used in tools that do data
profiling.
perf trace:
- Remove the old, experimental support for BPF events in which a .c
file was passed as an event: "perf trace -e hello.c" to then get
compiled and loaded.
The only known usage for that, that shipped with the kernel as an
example for such events, augmented the raw_syscalls tracepoints and
was converted to a libbpf skeleton, reusing all the user space
components and the BPF code connected to the syscalls.
In the end just the way to glue the BPF part and the user space
type beautifiers changed, now being performed by libbpf skeletons.
The next step is to use BTF to do pretty printing of all syscall
types, as discussed with Alan Maguire and others.
Now, on a perf built with BUILD_BPF_SKEL=1 we get most if not all
path/filenames/strings, some of the networking data structures,
perf_event_attr, etc, i.e. systemwide tracing of nanosleep calls
and perf_event_open syscalls while 'perf stat' runs 'sleep' for 5
seconds:
# perf trace -a -e *nanosleep,perf* perf stat -e cycles,instructions sleep 5
0.000 ( 9.034 ms): perf/327641 perf_event_open(attr_uptr: { type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0 (PERF_COUNT_HW_CPU_CYCLES), sample_type: IDENTIFIER, read_format: TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING, disabled: 1, inherit: 1, enable_on_exec: 1, exclude_guest: 1 }, pid: 327642 (perf), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 3
9.039 ( 0.006 ms): perf/327641 perf_event_open(attr_uptr: { type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0x1 (PERF_COUNT_HW_INSTRUCTIONS), sample_type: IDENTIFIER, read_format: TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING, disabled: 1, inherit: 1, enable_on_exec: 1, exclude_guest: 1 }, pid: 327642 (perf-exec), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
? ( ): gpm/991 ... [continued]: clock_nanosleep()) = 0
10.133 ( ): sleep/327642 clock_nanosleep(rqtp: { .tv_sec: 5, .tv_nsec: 0 }, rmtp: 0x7ffd36f83ed0) ...
? ( ): pool-gsd-smart/3051 ... [continued]: clock_nanosleep()) = 0
30.276 ( ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
223.215 (1000.430 ms): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) = 0
30.276 (2000.394 ms): gpm/991 ... [continued]: clock_nanosleep()) = 0
1230.814 ( ): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) ...
1230.814 (1000.404 ms): pool-gsd-smart/3051 ... [continued]: clock_nanosleep()) = 0
2030.886 ( ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
2237.709 (1000.153 ms): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) = 0
? ( ): crond/1172 ... [continued]: clock_nanosleep()) = 0
3242.699 ( ): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) ...
2030.886 (2000.385 ms): gpm/991 ... [continued]: clock_nanosleep()) = 0
3728.078 ( ): crond/1172 clock_nanosleep(rqtp: { .tv_sec: 60, .tv_nsec: 0 }, rmtp: 0x7ffe0971dcf0) ...
3242.699 (1000.158 ms): pool-gsd-smart/3051 ... [continued]: clock_nanosleep()) = 0
4031.409 ( ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
10.133 (5000.375 ms): sleep/327642 ... [continued]: clock_nanosleep()) = 0
Performance counter stats for 'sleep 5':
2,617,347 cycles
1,855,997 instructions # 0.71 insn per cycle
5.002282128 seconds time elapsed
0.000855000 seconds user
0.000852000 seconds sys
perf annotate:
- Building with binutils' libopcode now is opt-in (BUILD_NONDISTRO=1)
for licensing reasons, and we missed a build test on
tools/perf/tests makefile.
Since we now default to NDEBUG=1, we ended up segfaulting when
building with BUILD_NONDISTRO=1 because a needed initialization
routine was being "error checked" via an assert.
Fix it by explicitly checking the result and aborting instead if it
fails.
We better back propagate the error, but at least 'perf annotate' on
samples collected for a BPF program is back working when perf is
built with BUILD_NONDISTRO=1.
perf report/top:
- Add back TUI hierarchy mode header, that is seen when using 'perf
report/top --hierarchy'.
- Fix the number of entries for 'e' key in the TUI that was
preventing navigation of lines when expanding an entry.
perf report/script:
- Support cross platform register handling, allowing a perf.data file
collected on one architecture to have registers sampled correctly
displayed when analysis tools such as 'perf report' and 'perf
script' are used on a different architecture.
- Fix handling of event attributes in pipe mode, i.e. when one uses:
perf record -o - | perf report -i -
When no perf.data files are used.
- Handle files generated via pipe mode with a version of perf and
then read also via pipe mode with a different version of perf,
where the event attr record may have changed, use the record size
field to properly support this version mismatch.
perf probe:
- Accessing global variables from uprobes isn't supported, make the
error message state that instead of stating that some minimal
kernel version is needed to have that feature. This seems just a
tool limitation, the kernel probably has all that is needed.
perf tests:
- Fix a reference count related leak in the dlfilter v0 API where the
result of a thread__find_symbol_fb() is not matched with an
addr_location__exit() to drop the reference counts of the resolved
components (machine, thread, map, symbol, etc). Add a dlfilter test
to make sure that doesn't regresses.
- Lots of fixes for the 'perf test' written in shell script related
to problems found with the shellcheck utility.
- Fixes for 'perf test' shell scripts testing features enabled when
perf is built with BUILD_BPF_SKEL=1, such as 'perf stat' bpf
counters.
- Add perf record sample filtering test, things like the following
example, that gets implemented as a BPF filter attached to the
event:
# perf record -e task-clock -c 10000 --filter 'ip < 0xffffffff00000000'
- Improve the way the task_analyzer test checks if libtraceevent is
linked, using 'perf version --build-options' instead of the more
expensinve 'perf record -e "sched:sched_switch"'.
- Add support for riscv in the mmap-basic test. (This went as well
via the RiscV tree, same contents).
libperf:
- Implement riscv mmap support (This went as well via the RiscV tree,
same contents).
perf script:
- New tool that converts perf.data files to the firefox profiler
format so that one can use the visualizer at
https://profiler.firefox.com/. Done by Anup Sharma as part of this
year's Google Summer of Code.
One can generate the output and upload it to the web interface but
Anup also automated everything:
perf script gecko -F 99 -a sleep 60
- Support syscall name parsing on arm64.
- Print "cgroup" field on the same line as "comm".
perf bench:
- Add new 'uprobe' benchmark to measure the overhead of uprobes
with/without BPF programs attached to it.
- breakpoints are not available on power9, skip that test.
perf stat:
- Add #num_cpus_online literal to be used in 'perf stat' metrics, and
add this extra 'perf test' check that exemplifies its purpose:
TEST_ASSERT_VAL("#num_cpus_online",
expr__parse(&num_cpus_online, ctx, "#num_cpus_online") == 0);
TEST_ASSERT_VAL("#num_cpus", expr__parse(&num_cpus, ctx, "#num_cpus") == 0);
TEST_ASSERT_VAL("#num_cpus >= #num_cpus_online", num_cpus >= num_cpus_online);
Miscellaneous:
- Improve tool startup time by lazily reading PMU, JSON, sysfs data.
- Improve error reporting in the parsing of events, passing YYLTYPE
to error routines, so that the output can show were the parsing
error was found.
- Add 'perf test' entries to check the parsing of events
improvements.
- Fix various leak for things detected by -fsanitize=address, mostly
things that would be freed at tool exit, including:
- Free evsel->filter on the destructor.
- Allow tools to register a thread->priv destructor and use it in
'perf trace'.
- Free evsel->priv in 'perf trace'.
- Free string returned by synthesize_perf_probe_point() when the
caller fails to do all it needs.
- Adjust various compiler options to not consider errors some
warnings when building with broken headers found in things like
python, flex, bison, as we otherwise build with -Werror. Some for
gcc, some for clang, some for some specific version of those, some
for some specific version of flex or bison, or some specific
combination of these components, bah.
- Allow customization of clang options for BPF target, this helps
building on gentoo where there are other oddities where BPF targets
gets passed some compiler options intended for the native build, so
building with WERROR=0 helps while these oddities are fixed.
- Dont pass ERR_PTR() values to perf_session__delete() in 'perf top'
and 'perf lock', fixing some segfaults when handling some odd
failures.
- Add LTO build option.
- Fix format of unordered lists in the perf docs
(tools/perf/Documentation)
- Overhaul the bison files, using constructs such as YYNOMEM.
- Remove unused tokens from the bison .y files.
- Add more comments to various structs.
- A few LoongArch enablement patches.
Vendor events (JSON):
- Add JSON metrics for Yitian 710 DDR (aarch64). Things like:
EventName, BriefDescription
visible_window_limit_reached_rd, "At least one entry in read queue reaches the visible window limit.",
visible_window_limit_reached_wr, "At least one entry in write queue reaches the visible window limit.",
op_is_dqsosc_mpc , "A DQS Oscillator MPC command to DRAM.",
op_is_dqsosc_mrr , "A DQS Oscillator MRR command to DRAM.",
op_is_tcr_mrr , "A Temperature Compensated Refresh(TCR) MRR command to DRAM.",
- Add AmpereOne metrics (aarch64).
- Update N2 and V2 metrics (aarch64) and events using Arm telemetry
repo.
- Update scale units and descriptions of common topdown metrics on
aarch64. Things like:
- "MetricExpr": "stall_slot_frontend / (#slots * cpu_cycles)",
- "BriefDescription": "Frontend bound L1 topdown metric",
+ "MetricExpr": "100 * (stall_slot_frontend / (#slots * cpu_cycles))",
+ "BriefDescription": "This metric is the percentage of total slots that were stalled due to resource constraints in the frontend of the processor.",
- Update events for intel: meteorlake to 1.04, sapphirerapids to
1.15, Icelake+ metric constraints.
- Update files for the power10 platform"
* tag 'perf-tools-for-v6.6-1-2023-09-05' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (217 commits)
perf parse-events: Fix driver config term
perf parse-events: Fixes relating to no_value terms
perf parse-events: Fix propagation of term's no_value when cloning
perf parse-events: Name the two term enums
perf list: Don't print Unit for "default_core"
perf vendor events intel: Fix modifier in tma_info_system_mem_parallel_reads for skylake
perf dlfilter: Avoid leak in v0 API test use of resolve_address()
perf metric: Add #num_cpus_online literal
perf pmu: Remove str from perf_pmu_alias
perf parse-events: Make common term list to strbuf helper
perf parse-events: Minor help message improvements
perf pmu: Avoid uninitialized use of alias->str
perf jevents: Use "default_core" for events with no Unit
perf test stat_bpf_counters_cgrp: Enhance perf stat cgroup BPF counter test
perf test shell stat_bpf_counters: Fix test on Intel
perf test shell record_bpf_filter: Skip 6.2 kernel
libperf: Get rid of attr.id field
perf tools: Convert to perf_record_header_attr_id()
libperf: Add perf_record_header_attr_id()
perf tools: Handle old data in PERF_RECORD_ATTR
...
Pull smb client fixes from Steve French:
- six smb3 client fixes including ones to allow controlling smb3
directory caching timeout and limits, and one debugging improvement
- one fix for nls Kconfig (don't need to expose NLS_UCS2_UTILS option)
- one minor spnego registry update
* tag '6.6-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
spnego: add missing OID to oid registry
smb3: fix minor typo in SMB2_GLOBAL_CAP_LARGE_MTU
cifs: update internal module version number for cifs.ko
smb3: allow controlling maximum number of cached directories
smb3: add trace point for queryfs (statfs)
nls: Hide new NLS_UCS2_UTILS
smb3: allow controlling length of time directory entries are cached with dir leases
smb: propagate error code of extract_sharename()
iov_iter_extract_pages() doesn't correctly handle skipping over initial
zero-length entries in ITER_KVEC and ITER_BVEC-type iterators.
The problem is that it accidentally reduces maxsize to 0 when it
skipping and thus runs to the end of the array and returns 0.
Fix this by sticking the calculated size-to-copy in a new variable
rather than back in maxsize.
Fixes: 7d58fe7310 ("iov_iter: Add a function to extract a page list from an iterator")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull sh updates from Adrian Glaubitz:
- Fix a use-after-free bug in the push-switch driver (Duoming Zhou)
- Fix calls to dma_declare_coherent_memory() that incorrectly passed
the buffer end address instead of the buffer size as the size
parameter
* tag 'sh-for-v6.6-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux:
sh: push-switch: Reorder cleanup operations to avoid use-after-free bug
sh: boards: Fix CEU buffer size passed to dma_declare_coherent_memory()
Pull more RISC-V updates from Palmer Dabbelt:
- The kernel now dynamically probes for misaligned access speed, as
opposed to relying on a table of known implementations.
- Support for non-coherent devices on systems using the Andes AX45MP
core, including the RZ/Five SoCs.
- Support for the V extension in ptrace(), again.
- Support for KASLR.
- Support for the BPF prog pack allocator in RISC-V.
- A handful of bug fixes and cleanups.
* tag 'riscv-for-linus-6.6-mw2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (25 commits)
soc: renesas: Kconfig: For ARCH_R9A07G043 select the required configs if dependencies are met
riscv: Kconfig.errata: Add dependency for RISCV_SBI in ERRATA_ANDES config
riscv: Kconfig.errata: Drop dependency for MMU in ERRATA_ANDES_CMO config
riscv: Kconfig: Select DMA_DIRECT_REMAP only if MMU is enabled
bpf, riscv: use prog pack allocator in the BPF JIT
riscv: implement a memset like function for text
riscv: extend patch_text_nosync() for multiple pages
bpf: make bpf_prog_pack allocator portable
riscv: libstub: Implement KASLR by using generic functions
libstub: Fix compilation warning for rv32
arm64: libstub: Move KASLR handling functions to kaslr.c
riscv: Dump out kernel offset information on panic
riscv: Introduce virtual kernel mapping KASLR
RISC-V: Add ptrace support for vectors
soc: renesas: Kconfig: Select the required configs for RZ/Five SoC
cache: Add L2 cache management for Andes AX45MP RISC-V core
dt-bindings: cache: andestech,ax45mp-cache: Add DT binding documentation for L2 cache controller
riscv: mm: dma-noncoherent: nonstandard cache operations support
riscv: errata: Add Andes alternative ports
riscv: asm: vendorid_list: Add Andes Technology to the vendors list
...
The original code puts flush_work() before timer_shutdown_sync()
in switch_drv_remove(). Although we use flush_work() to stop
the worker, it could be rescheduled in switch_timer(). As a result,
a use-after-free bug can occur. The details are shown below:
(cpu 0) | (cpu 1)
switch_drv_remove() |
flush_work() |
... | switch_timer // timer
| schedule_work(&psw->work)
timer_shutdown_sync() |
... | switch_work_handler // worker
kfree(psw) // free |
| psw->state = 0 // use
This patch puts timer_shutdown_sync() before flush_work() to
mitigate the bugs. As a result, the worker and timer will be
stopped safely before the deallocate operations.
Fixes: 9f5e8eee5c ("sh: generic push-switch framework.")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20230802033737.9738-1-duoming@zju.edu.cn
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
