<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/tools/testing/selftests, branch v5.10.257</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.10.257</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.10.257'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-04-18T08:30:51+00:00</updated>
<entry>
<title>selftests: mptcp: more stable simult_flows tests</title>
<updated>2026-04-18T08:30:51+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2026-03-03T10:56:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ba587e6ca434e60e0993fffeb1139d1641594308'/>
<id>urn:sha1:ba587e6ca434e60e0993fffeb1139d1641594308</id>
<content type='text'>
commit 8c09412e584d9bcc0e71d758ec1008d1c8d1a326 upstream.

By default, the netem qdisc can keep up to 1000 packets under its belly
to deal with the configured rate and delay. The simult flows test-case
simulates very low speed links, to avoid problems due to slow CPUs and
the TCP stack tend to transmit at a slightly higher rate than the
(virtual) link constraints.

All the above causes a relatively large amount of packets being enqueued
in the netem qdiscs - the longer the transfer, the longer the queue -
producing increasingly high TCP RTT samples and consequently increasingly
larger receive buffer size due to DRS.

When the receive buffer size becomes considerably larger than the needed
size, the tests results can flake, i.e. because minimal inaccuracy in the
pacing rate can lead to a single subflow usage towards the end of the
connection for a considerable amount of data.

Address the issue explicitly setting netem limits suitable for the
configured link speeds and unflake all the affected tests.

Fixes: 1a418cb8e888 ("mptcp: simult flow self-tests")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Reviewed-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-1-4b5462b6f016@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>selftests/mm/charge_reserved_hugetlb: drop mount size for hugetlbfs</title>
<updated>2026-03-04T12:20:18+00:00</updated>
<author>
<name>Li Wang</name>
<email>liwang@redhat.com</email>
</author>
<published>2025-12-21T12:26:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=861b00da56a0c41eb35a1e276fb5fb1fb0aa306c'/>
<id>urn:sha1:861b00da56a0c41eb35a1e276fb5fb1fb0aa306c</id>
<content type='text'>
[ Upstream commit 1aa1dd9cc595917882fb6db67725442956f79607 ]

charge_reserved_hugetlb.sh mounts a hugetlbfs instance at /mnt/huge with a
fixed size of 256M.  On systems with large base hugepages (e.g.  512MB),
this is smaller than a single hugepage, so the hugetlbfs mount ends up
with zero capacity (often visible as size=0 in mount output).

As a result, write_to_hugetlbfs fails with ENOMEM and the test can hang
waiting for progress.

=== Error log ===
  # uname -r
  6.12.0-xxx.el10.aarch64+64k

  #./charge_reserved_hugetlb.sh -cgroup-v2
  # -----------------------------------------
  ...
  # nr hugepages = 10
  # writing cgroup limit: 5368709120
  # writing reseravation limit: 5368709120
  ...
  # write_to_hugetlbfs: Error mapping the file: Cannot allocate memory
  # Waiting for hugetlb memory reservation to reach size 2684354560.
  # 0
  # Waiting for hugetlb memory reservation to reach size 2684354560.
  # 0
  ...

  # mount |grep /mnt/huge
  none on /mnt/huge type hugetlbfs (rw,relatime,seclabel,pagesize=512M,size=0)

  # grep -i huge /proc/meminfo
  ...
  HugePages_Total:      10
  HugePages_Free:       10
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:     524288 kB
  Hugetlb:         5242880 kB

Drop the mount args with 'size=256M', so the filesystem capacity is sufficient
regardless of HugeTLB page size.

Link: https://lkml.kernel.org/r/20251221122639.3168038-3-liwang@redhat.com
Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: Li Wang &lt;liwang@redhat.com&gt;
Acked-by: David Hildenbrand (Red Hat) &lt;david@kernel.org&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests: forwarding: tc_actions: Use ncat instead of nc</title>
<updated>2026-03-04T12:19:47+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2023-08-08T14:14:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5cd2c60f9038187e2c95e027b7686054965d43ea'/>
<id>urn:sha1:5cd2c60f9038187e2c95e027b7686054965d43ea</id>
<content type='text'>
[ Upstream commit 5e8670610b93158ffacc3241f835454ff26a3469 ]

The test relies on 'nc' being the netcat version from the nmap project.
While this seems to be the case on Fedora, it is not the case on Ubuntu,
resulting in failures such as [1].

Fix by explicitly using the 'ncat' utility from the nmap project and the
skip the test in case it is not installed.

[1]
 # timeout set to 0
 # selftests: net/forwarding: tc_actions.sh
 # TEST: gact drop and ok (skip_hw)                                    [ OK ]
 # TEST: mirred egress flower redirect (skip_hw)                       [ OK ]
 # TEST: mirred egress flower mirror (skip_hw)                         [ OK ]
 # TEST: mirred egress matchall mirror (skip_hw)                       [ OK ]
 # TEST: mirred_egress_to_ingress (skip_hw)                            [ OK ]
 # nc: invalid option -- '-'
 # usage: nc [-46CDdFhklNnrStUuvZz] [-I length] [-i interval] [-M ttl]
 #         [-m minttl] [-O length] [-P proxy_username] [-p source_port]
 #         [-q seconds] [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit]
 #         [-w timeout] [-X proxy_protocol] [-x proxy_address[:port]]
 #         [destination] [port]
 # nc: invalid option -- '-'
 # usage: nc [-46CDdFhklNnrStUuvZz] [-I length] [-i interval] [-M ttl]
 #         [-m minttl] [-O length] [-P proxy_username] [-p source_port]
 #         [-q seconds] [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit]
 #         [-w timeout] [-X proxy_protocol] [-x proxy_address[:port]]
 #         [destination] [port]
 # TEST: mirred_egress_to_ingress_tcp (skip_hw)                        [FAIL]
 #       server output check failed
 # INFO: Could not test offloaded functionality
 not ok 80 selftests: net/forwarding: tc_actions.sh # exit=1

Fixes: ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress")
Reported-by: Mirsad Todorovac &lt;mirsad.todorovac@alu.unizg.hr&gt;
Closes: https://lore.kernel.org/netdev/adc5e40d-d040-a65e-eb26-edf47dac5b02@alu.unizg.hr/
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Petr Machata &lt;petrm@nvidia.com&gt;
Tested-by: Mirsad Todorovac &lt;mirsad.todorovac@alu.unizg.hr&gt;
Reviewed-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://lore.kernel.org/r/20230808141503.4060661-12-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Stable-dep-of: 32b70e62034a ("selftests: tc_actions: don't dump 2MB of \0 to stdout")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests: forwarding: tc_actions: cleanup temporary files when test is aborted</title>
<updated>2026-03-04T12:19:47+00:00</updated>
<author>
<name>Davide Caratti</name>
<email>dcaratti@redhat.com</email>
</author>
<published>2023-02-14T09:52:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8f89f8410030755a5190cfc42fb2d4f84c0aafdd'/>
<id>urn:sha1:8f89f8410030755a5190cfc42fb2d4f84c0aafdd</id>
<content type='text'>
[ Upstream commit f58531716ced8975a4ade108ef4af35f98722af7 ]

remove temporary files created by 'mirred_egress_to_ingress_tcp' test
in the cleanup() handler. Also, change variable names to avoid clashing
with globals from lib.sh.

Suggested-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Davide Caratti &lt;dcaratti@redhat.com&gt;
Link: https://lore.kernel.org/r/091649045a017fc00095ecbb75884e5681f7025f.1676368027.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Stable-dep-of: 32b70e62034a ("selftests: tc_actions: don't dump 2MB of \0 to stdout")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests: forwarding: vxlan_bridge_1d: fix test failure with br_netfilter enabled</title>
<updated>2026-03-04T12:19:46+00:00</updated>
<author>
<name>Aleksei Oladko</name>
<email>aleksey.oladko@virtuozzo.com</email>
</author>
<published>2026-02-13T13:19:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=bade4c20950ed1fcd9d62f66c06ee5bd6d33d1d9'/>
<id>urn:sha1:bade4c20950ed1fcd9d62f66c06ee5bd6d33d1d9</id>
<content type='text'>
[ Upstream commit 02cb2e6bacbb08ebf6acb61be816efd11e1f4a21 ]

The test generates VXLAN traffic using mausezahn, where the encapsulated
inner IPv4 packet contains a zero IP header checksum. After VXLAN
decapsulation, such packets do not pass sanity checks in br_netfilter
and are dropped, which causes the test to fail.

Fix this by calculating and setting a valid IPv4 header checksum for the
encapsulated packet generated by mausezahn, so that the packet is accepted
by br_netfilter. Fixed by using the payload_template_calc_checksum() /
payload_template_expand_checksum() helpers that are only available
in v6.3 and newer kernels.

Fixes: a0b61f3d8ebf ("selftests: forwarding: vxlan_bridge_1d: Add an ECN decap test")
Signed-off-by: Aleksei Oladko &lt;aleksey.oladko@virtuozzo.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20260213131907.43351-2-aleksey.oladko@virtuozzo.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests: mlxsw: tc_restrictions: Fix test failure with new iproute2</title>
<updated>2026-03-04T12:19:45+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2026-02-09T13:53:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=99c9d76fa21ffe5d9e4d91ab357f696265a99777'/>
<id>urn:sha1:99c9d76fa21ffe5d9e4d91ab357f696265a99777</id>
<content type='text'>
[ Upstream commit a2646773a005b59fd1dc7ff3ba15df84889ca5d2 ]

As explained in [1], iproute2 started rejecting tc-police burst sizes
that result in an overflow. This can happen when the burst size is high
enough and the rate is low enough.

A couple of test cases specify such configurations, resulting in
iproute2 errors and test failure.

Fix by reducing the burst size so that the test will pass with both new
and old iproute2 versions.

[1] https://lore.kernel.org/netdev/20250916215731.3431465-1-jay.vosburgh@canonical.com/

Fixes: cb12d1763267 ("selftests: mlxsw: tc_restrictions: Test tc-police restrictions")
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Link: https://patch.msgid.link/88b00c6e85188aa6a065dc240206119b328c46e1.1770643998.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests: mptcp: pm: ensure unknown flags are ignored</title>
<updated>2026-02-19T15:20:26+00:00</updated>
<author>
<name>Matthieu Baerts (NGI0)</name>
<email>matttbe@kernel.org</email>
</author>
<published>2026-02-12T11:50:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4a9b23e0f937329c00ef2e7803ec9aaf842db526'/>
<id>urn:sha1:4a9b23e0f937329c00ef2e7803ec9aaf842db526</id>
<content type='text'>
commit 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7 upstream.

This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781a6c1b8@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
[ Conflicts in pm_netlink.sh, because some refactoring have been done
  later on: commit 0d16ed0c2e74 ("selftests: mptcp: add
  {get,format}_endpoint(s) helpers") and commit c99d57d0007a
  ("selftests: mptcp: use pm_nl endpoint ops") are not in this version.
  The same operation can still be done at the same place, without using
  the new helpers.
  Also, commit 1dc88d241f92 ("selftests: mptcp: pm_nl_ctl: always look
  for errors") is not in this version, and create a conflict in the
  context which is not related to the modification here.
  In v5.10, endpoints couldn't be re-used directly, so the flag is
  tested before.
  Conflicts in pm_nl_ctl.c, because commit 69c6ce7b6eca ("selftests:
  mptcp: add implicit endpoint test case") and commit 371b90377e60
  ("selftests: mptcp: set and print the fullmesh flag") are not in this
  version, and caused a conflict in the context which is not related to
  the modification here. ]
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Revert "selftests: Replace sleep with slowwait"</title>
<updated>2026-02-06T15:40:14+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2026-02-04T14:02:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8143011dabbc3e4b66bcd647bc61caa8a185f07a'/>
<id>urn:sha1:8143011dabbc3e4b66bcd647bc61caa8a185f07a</id>
<content type='text'>
This reverts commit 780095c51e34ec7cdf6f651b4c4f2b35680779e4 which is
commit 2f186dd5585c3afb415df80e52f71af16c9d3655 upstream.

To quote Ben:
	The slowwait function isn't defined in 5.10 (or any stable
	branch older than 6.9).

Link: https://lore.kernel.org/r/b052b71589bb576dcad441eba38c20da81443a46.camel@decadent.org.uk
Reported-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: Simon Horman &lt;horms@kernel.org&gt;
Cc: Jakub Kicinski &lt;kuba@kernel.org&gt;
Cc: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>selftests/ftrace: traceonoff_triggers: strip off names</title>
<updated>2026-01-19T12:11:55+00:00</updated>
<author>
<name>Yipeng Zou</name>
<email>zouyipeng@huawei.com</email>
</author>
<published>2023-08-18T01:32:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2dc65cf1a494f721670c3647899a00ae5a6db04e'/>
<id>urn:sha1:2dc65cf1a494f721670c3647899a00ae5a6db04e</id>
<content type='text'>
[ Upstream commit b889b4fb4cbea3ca7eb9814075d6a51936394bd9 ]

The func_traceonoff_triggers.tc sometimes goes to fail
on my board, Kunpeng-920.

[root@localhost]# ./ftracetest ./test.d/ftrace/func_traceonoff_triggers.tc -l fail.log
=== Ftrace unit tests ===
[1] ftrace - test for function traceon/off triggers     [FAIL]
[2] (instance)  ftrace - test for function traceon/off triggers [UNSUPPORTED]

I look up the log, and it shows that the md5sum is different between csum1 and csum2.

++ cnt=611
++ sleep .1
+++ cnt_trace
+++ grep -v '^#' trace
+++ wc -l
++ cnt2=611
++ '[' 611 -ne 611 ']'
+++ cat tracing_on
++ on=0
++ '[' 0 '!=' 0 ']'
+++ md5sum trace
++ csum1='76896aa74362fff66a6a5f3cf8a8a500  trace'
++ sleep .1
+++ md5sum trace
++ csum2='ee8625a21c058818fc26e45c1ed3f6de  trace'
++ '[' '76896aa74362fff66a6a5f3cf8a8a500  trace' '!=' 'ee8625a21c058818fc26e45c1ed3f6de  trace' ']'
++ fail 'Tracing file is still changing'
++ echo Tracing file is still changing
Tracing file is still changing
++ exit_fail
++ exit 1

So I directly dump the trace file before md5sum, the diff shows that:

[root@localhost]# diff trace_1.log trace_2.log -y --suppress-common-lines
dockerd-12285   [036] d.... 18385.510290: sched_stat | &lt;...&gt;-12285   [036] d.... 18385.510290: sched_stat
dockerd-12285   [036] d.... 18385.510291: sched_swit | &lt;...&gt;-12285   [036] d.... 18385.510291: sched_swit
&lt;...&gt;-740       [044] d.... 18385.602859: sched_stat | kworker/44:1-740 [044] d.... 18385.602859: sched_stat
&lt;...&gt;-740       [044] d.... 18385.602860: sched_swit | kworker/44:1-740 [044] d.... 18385.602860: sched_swit

And we can see that &lt;...&gt; filed be filled with names.

We can strip off the names there to fix that.

After strip off the names:

kworker/u257:0-12 [019] d..2.  2528.758910: sched_stat | -12 [019] d..2.  2528.758910: sched_stat_runtime: comm=k
kworker/u257:0-12 [019] d..2.  2528.758912: sched_swit | -12 [019] d..2.  2528.758912: sched_switch: prev_comm=kw
&lt;idle&gt;-0          [000] d.s5.  2528.762318: sched_waki | -0  [000] d.s5.  2528.762318: sched_waking: comm=sshd pi
&lt;idle&gt;-0          [037] dNh2.  2528.762326: sched_wake | -0  [037] dNh2.  2528.762326: sched_wakeup: comm=sshd pi
&lt;idle&gt;-0          [037] d..2.  2528.762334: sched_swit | -0  [037] d..2.  2528.762334: sched_switch: prev_comm=sw

Link: https://lore.kernel.org/r/20230818013226.2182299-1-zouyipeng@huawei.com
Fixes: d87b29179aa0 ("selftests: ftrace: Use md5sum to take less time of checking logs")
Suggested-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Yipeng Zou &lt;zouyipeng@huawei.com&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Reviewed-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/bpf: Improve reliability of test_perf_branches_no_hw()</title>
<updated>2026-01-19T12:11:33+00:00</updated>
<author>
<name>Matt Bobrowski</name>
<email>mattbobrowski@google.com</email>
</author>
<published>2025-11-19T14:35:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8f5d073be1b6334ae9ac52a08b72e00cab0904bd'/>
<id>urn:sha1:8f5d073be1b6334ae9ac52a08b72e00cab0904bd</id>
<content type='text'>
[ Upstream commit ae24fc8a16b0481ea8c5acbc66453c49ec0431c4 ]

Currently, test_perf_branches_no_hw() relies on the busy loop within
test_perf_branches_common() being slow enough to allow at least one
perf event sample tick to occur before starting to tear down the
backing perf event BPF program. With a relatively small fixed
iteration count of 1,000,000, this is not guaranteed on modern fast
CPUs, resulting in the test run to subsequently fail with the
following:

bpf_testmod.ko is already unloaded.
Loading bpf_testmod.ko...
Successfully loaded bpf_testmod.ko.
test_perf_branches_common:PASS:test_perf_branches_load 0 nsec
test_perf_branches_common:PASS:attach_perf_event 0 nsec
test_perf_branches_common:PASS:set_affinity 0 nsec
check_good_sample:PASS:output not valid 0 nsec
check_good_sample:PASS:read_branches_size 0 nsec
check_good_sample:PASS:read_branches_stack 0 nsec
check_good_sample:PASS:read_branches_stack 0 nsec
check_good_sample:PASS:read_branches_global 0 nsec
check_good_sample:PASS:read_branches_global 0 nsec
check_good_sample:PASS:read_branches_size 0 nsec
test_perf_branches_no_hw:PASS:perf_event_open 0 nsec
test_perf_branches_common:PASS:test_perf_branches_load 0 nsec
test_perf_branches_common:PASS:attach_perf_event 0 nsec
test_perf_branches_common:PASS:set_affinity 0 nsec
check_bad_sample:FAIL:output not valid no valid sample from prog
Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED
Successfully unloaded bpf_testmod.ko.

On a modern CPU (i.e. one with a 3.5 GHz clock rate), executing 1
million increments of a volatile integer can take significantly less
than 1 millisecond. If the spin loop and detachment of the perf event
BPF program elapses before the first 1 ms sampling interval elapses,
the perf event will never end up firing. Fix this by bumping the loop
iteration counter a little within test_perf_branches_common(), along
with ensuring adding another loop termination condition which is
directly influenced by the backing perf event BPF program
executing. Notably, a concious decision was made to not adjust the
sample_freq value as that is just not a reliable way to go about
fixing the problem. It effectively still leaves the race window open.

Fixes: 67306f84ca78c ("selftests/bpf: Add bpf_read_branch_records() selftest")
Signed-off-by: Matt Bobrowski &lt;mattbobrowski@google.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/r/20251119143540.2911424-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
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