<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/kernel/events, branch v6.6.32</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2024-02-05T20:14:33Z</updated>
<entry>
<title>perf: Fix the nr_addr_filters fix</title>
<updated>2024-02-05T20:14:33Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-11-22T10:07:56Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2d5228be5e03bb23d11381d7a13bd6e2a585fd1b'/>
<id>urn:sha1:2d5228be5e03bb23d11381d7a13bd6e2a585fd1b</id>
<content type='text'>
[ Upstream commit 388a1fb7da6aaa1970c7e2a7d7fcd983a87a8484 ]

Thomas reported that commit 652ffc2104ec ("perf/core: Fix narrow
startup race when creating the perf nr_addr_filters sysfs file") made
the entire attribute group vanish, instead of only the nr_addr_filters
attribute.

Additionally a stray return.

Insufficient coffee was involved with both writing and merging the
patch.

Fixes: 652ffc2104ec ("perf/core: Fix narrow startup race when creating the perf nr_addr_filters sysfs file")
Reported-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Link: https://lkml.kernel.org/r/20231122100756.GP8262@noisy.programming.kicks-ass.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/core: Fix narrow startup race when creating the perf nr_addr_filters sysfs file</title>
<updated>2024-02-05T20:14:14Z</updated>
<author>
<name>Greg KH</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-06-12T13:09:09Z</published>
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<id>urn:sha1:814173380135834d8e520cb2fa45951205744cf3</id>
<content type='text'>
[ Upstream commit 652ffc2104ec1f69dd4a46313888c33527145ccf ]

Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/2023061204-decal-flyable-6090@gregkh
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf: Fix perf_event_validate_size() lockdep splat</title>
<updated>2023-12-20T16:02:01Z</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2023-12-15T11:24:50Z</published>
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<id>urn:sha1:545d55a3e0c8f4e59fbc9d92c99ef5725c799014</id>
<content type='text'>
commit 7e2c1e4b34f07d9aa8937fab88359d4a0fce468e upstream.

When lockdep is enabled, the for_each_sibling_event(sibling, event)
macro checks that event-&gt;ctx-&gt;mutex is held. When creating a new group
leader event, we call perf_event_validate_size() on a partially
initialized event where event-&gt;ctx is NULL, and so when
for_each_sibling_event() attempts to check event-&gt;ctx-&gt;mutex, we get a
splat, as reported by Lucas De Marchi:

  WARNING: CPU: 8 PID: 1471 at kernel/events/core.c:1950 __do_sys_perf_event_open+0xf37/0x1080

This only happens for a new event which is its own group_leader, and in
this case there cannot be any sibling events. Thus it's safe to skip the
check for siblings, which avoids having to make invasive and ugly
changes to for_each_sibling_event().

Avoid the splat by bailing out early when the new event is its own
group_leader.

Fixes: 382c27f4ed28f803 ("perf: Fix perf_event_validate_size()")
Closes: https://lore.kernel.org/lkml/20231214000620.3081018-1-lucas.demarchi@intel.com/
Closes: https://lore.kernel.org/lkml/ZXpm6gQ%2Fd59jGsuW@xpf.sh.intel.com/
Reported-by: Lucas De Marchi &lt;lucas.demarchi@intel.com&gt;
Reported-by: Pengfei Xu &lt;pengfei.xu@intel.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20231215112450.3972309-1-mark.rutland@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf: Fix perf_event_validate_size()</title>
<updated>2023-12-13T17:45:30Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-11-29T14:24:52Z</published>
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<id>urn:sha1:cfe9295db0932f1b8e0d94ffc75521898e5a5a8a</id>
<content type='text'>
[ Upstream commit 382c27f4ed28f803b1f1473ac2d8db0afc795a1b ]

Budimir noted that perf_event_validate_size() only checks the size of
the newly added event, even though the sizes of all existing events
can also change due to not all events having the same read_format.

When we attach the new event, perf_group_attach(), we do re-compute
the size for all events.

Fixes: a723968c0ed3 ("perf: Fix u16 overflows")
Reported-by: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/core: Fix cpuctx refcounting</title>
<updated>2023-11-28T17:19:54Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-06-09T10:34:46Z</published>
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<id>urn:sha1:2635504d913f5c66d8853a12eb8eb852b5552824</id>
<content type='text'>
commit 889c58b3155ff4c8e8671c95daef63d6fabbb6b1 upstream.

Audit of the refcounting turned up that perf_pmu_migrate_context()
fails to migrate the ctx refcount.

Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lkml.kernel.org/r/20230612093539.085862001@infradead.org
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf/core: Bail out early if the request AUX area is out of bound</title>
<updated>2023-11-28T17:19:36Z</updated>
<author>
<name>Shuai Xue</name>
<email>xueshuai@linux.alibaba.com</email>
</author>
<published>2023-09-07T00:43:07Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2e905e608e38cf7f8dcddcf8a6036e91a78444cb'/>
<id>urn:sha1:2e905e608e38cf7f8dcddcf8a6036e91a78444cb</id>
<content type='text'>
[ Upstream commit 54aee5f15b83437f23b2b2469bcf21bdd9823916 ]

When perf-record with a large AUX area, e.g 4GB, it fails with:

    #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
    failed to mmap with 12 (Cannot allocate memory)

and it reveals a WARNING with __alloc_pages():

	------------[ cut here ]------------
	WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248
	Call trace:
	 __alloc_pages+0x1ec/0x248
	 __kmalloc_large_node+0xc0/0x1f8
	 __kmalloc_node+0x134/0x1e8
	 rb_alloc_aux+0xe0/0x298
	 perf_mmap+0x440/0x660
	 mmap_region+0x308/0x8a8
	 do_mmap+0x3c0/0x528
	 vm_mmap_pgoff+0xf4/0x1b8
	 ksys_mmap_pgoff+0x18c/0x218
	 __arm64_sys_mmap+0x38/0x58
	 invoke_syscall+0x50/0x128
	 el0_svc_common.constprop.0+0x58/0x188
	 do_el0_svc+0x34/0x50
	 el0_svc+0x34/0x108
	 el0t_64_sync_handler+0xb8/0xc0
	 el0t_64_sync+0x1a4/0x1a8

'rb-&gt;aux_pages' allocated by kcalloc() is a pointer array which is used to
maintains AUX trace pages. The allocated page for this array is physically
contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the
size of pointer array crosses the limitation set by MAX_ORDER, it reveals a
WARNING.

So bail out early with -ENOMEM if the request AUX area is out of bound,
e.g.:

    #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
    failed to mmap with 12 (Cannot allocate memory)

Signed-off-by: Shuai Xue &lt;xueshuai@linux.alibaba.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf: Optimize perf_cgroup_switch()</title>
<updated>2023-11-20T10:58:53Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-10-09T21:04:25Z</published>
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<id>urn:sha1:b0ebeb5956e5eae19c1520fb78197a252aabc4c3</id>
<content type='text'>
[ Upstream commit f06cc667f79909e9175460b167c277b7c64d3df0 ]

Namhyung reported that bd2756811766 ("perf: Rewrite core context handling")
regresses context switch overhead when perf-cgroup is in use together
with 'slow' PMUs like uncore.

Specifically, perf_cgroup_switch()'s perf_ctx_disable() /
ctx_sched_out() etc.. all iterate the full list of active PMUs for
that CPU, even if they don't have cgroup events.

Previously there was cgrp_cpuctx_list which linked the relevant PMUs
together, but that got lost in the rework. Instead of re-instruducing
a similar list, let the perf_event_pmu_context iteration skip those
that do not have cgroup events. This avoids growing multiple versions
of the perf_event_pmu_context iteration.

Measured performance (on a slightly different patch):

Before)

  $ taskset -c 0 ./perf bench sched pipe -l 10000 -G AAA,BBB
  # Running 'sched/pipe' benchmark:
  # Executed 10000 pipe operations between two processes

       Total time: 0.901 [sec]

        90.128700 usecs/op
            11095 ops/sec

After)

  $ taskset -c 0 ./perf bench sched pipe -l 10000 -G AAA,BBB
  # Running 'sched/pipe' benchmark:
  # Executed 10000 pipe operations between two processes

       Total time: 0.065 [sec]

         6.560100 usecs/op
           152436 ops/sec

Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Debugged-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20231009210425.GC6307@noisy.programming.kicks-ass.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/core: Fix potential NULL deref</title>
<updated>2023-10-24T10:15:12Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-10-24T09:42:21Z</published>
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<id>urn:sha1:a71ef31485bb51b846e8db8b3a35e432cc15afb5</id>
<content type='text'>
Smatch is awesome.

Fixes: 32671e3799ca ("perf: Disallow mis-matched inherited group reads")
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf: Disallow mis-matched inherited group reads</title>
<updated>2023-10-19T08:09:42Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-10-18T11:56:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=32671e3799ca2e4590773fd0e63aaa4229e50c06'/>
<id>urn:sha1:32671e3799ca2e4590773fd0e63aaa4229e50c06</id>
<content type='text'>
Because group consistency is non-atomic between parent (filedesc) and children
(inherited) events, it is possible for PERF_FORMAT_GROUP read() to try and sum
non-matching counter groups -- with non-sensical results.

Add group_generation to distinguish the case where a parent group removes and
adds an event and thus has the same number, but a different configuration of
events as inherited groups.

This became a problem when commit fa8c269353d5 ("perf/core: Invert
perf_read_group() loops") flipped the order of child_list and sibling_list.
Previously it would iterate the group (sibling_list) first, and for each
sibling traverse the child_list. In this order, only the group composition of
the parent is relevant. By flipping the order the group composition of the
child (inherited) events becomes an issue and the mis-match in group
composition becomes evident.

That said; even prior to this commit, while reading of a group that is not
equally inherited was not broken, it still made no sense.

(Ab)use ECHILD as error return to indicate issues with child process group
composition.

Fixes: fa8c269353d5 ("perf/core: Invert perf_read_group() loops")
Reported-by: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20231018115654.GK33217@noisy.programming.kicks-ass.net
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2023-08-31T19:43:10Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-08-31T19:43:10Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4ad0a4c2343d3981e92df2b39fa262be62a9091a'/>
<id>urn:sha1:4ad0a4c2343d3981e92df2b39fa262be62a9091a</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Add HOTPLUG_SMT support (/sys/devices/system/cpu/smt) and honour the
   configured SMT state when hotplugging CPUs into the system

 - Combine final TLB flush and lazy TLB mm shootdown IPIs when using the
   Radix MMU to avoid a broadcast TLBIE flush on exit

 - Drop the exclusion between ptrace/perf watchpoints, and drop the now
   unused associated arch hooks

 - Add support for the "nohlt" command line option to disable CPU idle

 - Add support for -fpatchable-function-entry for ftrace, with GCC &gt;=
   13.1

 - Rework memory block size determination, and support 256MB size on
   systems with GPUs that have hotpluggable memory

 - Various other small features and fixes

Thanks to Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira
Rajeev, Benjamin Gray, Christophe Leroy, Frederic Barrat, Gautam
Menghani, Geoff Levand, Hari Bathini, Immad Mir, Jialin Zhang, Joel
Stanley, Jordan Niethe, Justin Stitt, Kajol Jain, Kees Cook, Krzysztof
Kozlowski, Laurent Dufour, Liang He, Linus Walleij, Mahesh Salgaonkar,
Masahiro Yamada, Michal Suchanek, Nageswara R Sastry, Nathan Chancellor,
Nathan Lynch, Naveen N Rao, Nicholas Piggin, Nick Desaulniers, Omar
Sandoval, Randy Dunlap, Reza Arbab, Rob Herring, Russell Currey, Sourabh
Jain, Thomas Gleixner, Trevor Woerner, Uwe Kleine-König, Vaibhav Jain,
Xiongfeng Wang, Yuan Tan, Zhang Rui, and Zheng Zengkai.

* tag 'powerpc-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (135 commits)
  macintosh/ams: linux/platform_device.h is needed
  powerpc/xmon: Reapply "Relax frame size for clang"
  powerpc/mm/book3s64: Use 256M as the upper limit with coherent device memory attached
  powerpc/mm/book3s64: Fix build error with SPARSEMEM disabled
  powerpc/iommu: Fix notifiers being shared by PCI and VIO buses
  powerpc/mpc5xxx: Add missing fwnode_handle_put()
  powerpc/config: Disable SLAB_DEBUG_ON in skiroot
  powerpc/pseries: Remove unused hcall tracing instruction
  powerpc/pseries: Fix hcall tracepoints with JUMP_LABEL=n
  powerpc: dts: add missing space before {
  powerpc/eeh: Use pci_dev_id() to simplify the code
  powerpc/64s: Move CPU -mtune options into Kconfig
  powerpc/powermac: Fix unused function warning
  powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT
  powerpc: Don't include lppaca.h in paca.h
  powerpc/pseries: Move hcall_vphn() prototype into vphn.h
  powerpc/pseries: Move VPHN constants into vphn.h
  cxl: Drop unused detach_spa()
  powerpc: Drop zalloc_maybe_bootmem()
  powerpc/powernv: Use struct opal_prd_msg in more places
  ...
</content>
</entry>
</feed>
