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84f254d901
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Kajol Jain 84f254d901 tools/perf: Update call stack check in builtin-lock.c 
[ Upstream commit d7c9ae8d5d ]

The perf test named "kernel lock contention analysis test"
fails in powerpc system with below error:

  [command]# ./perf test 81 -vv
   81: kernel lock contention analysis test                            :
   --- start ---
  test child forked, pid 2140
  Testing perf lock record and perf lock contention
  Testing perf lock contention --use-bpf
  [Skip] No BPF support
  Testing perf lock record and perf lock contention at the same time
  Testing perf lock contention --threads
  Testing perf lock contention --lock-addr
  Testing perf lock contention --type-filter (w/ spinlock)
  Testing perf lock contention --lock-filter (w/ tasklist_lock)
  Testing perf lock contention --callstack-filter (w/ unix_stream)
  [Fail] Recorded result should have a lock from unix_stream:
  test child finished with -1
   ---- end ----
  kernel lock contention analysis test: FAILED!

The test is failing because we get an address entry with 0 in
perf lock samples for powerpc, and code for lock contention
option "--callstack-filter" will not check further entries after
address 0.

Below are some of the samples from test generated perf.data file, which
have 0 address in the 2nd entry of callstack:
 --------
sched-messaging    3409 [001]  7152.904029: lock:contention_begin: 0xc00000c80904ef00 (flags=SPIN)
        c0000000001e926c __traceiter_contention_begin+0x6c ([kernel.kallsyms])
                       0 [unknown] ([unknown])
        c000000000f8a178 native_queued_spin_lock_slowpath+0x1f8 ([kernel.kallsyms])
        c000000000f89f44 _raw_spin_lock_irqsave+0x84 ([kernel.kallsyms])
        c0000000001d9fd0 prepare_to_wait+0x50 ([kernel.kallsyms])
        c000000000c80f50 sock_alloc_send_pskb+0x1b0 ([kernel.kallsyms])
        c000000000e82298 unix_stream_sendmsg+0x2b8 ([kernel.kallsyms])
        c000000000c78980 sock_sendmsg+0x80 ([kernel.kallsyms])

sched-messaging    3408 [005]  7152.904036: lock:contention_begin: 0xc00000c80904ef00 (flags=SPIN)
        c0000000001e926c __traceiter_contention_begin+0x6c ([kernel.kallsyms])
                       0 [unknown] ([unknown])
        c000000000f8a178 native_queued_spin_lock_slowpath+0x1f8 ([kernel.kallsyms])
        c000000000f89f44 _raw_spin_lock_irqsave+0x84 ([kernel.kallsyms])
        c0000000001d9fd0 prepare_to_wait+0x50 ([kernel.kallsyms])
        c000000000c80f50 sock_alloc_send_pskb+0x1b0 ([kernel.kallsyms])
        c000000000e82298 unix_stream_sendmsg+0x2b8 ([kernel.kallsyms])
        c000000000c78980 sock_sendmsg+0x80 ([kernel.kallsyms])
 --------

Based on commit 20002ded4d ("perf_counter: powerpc: Add callchain support"),
incase of powerpc, the callchain saved by kernel always includes first
three entries as the NIP (next instruction pointer), LR (link register), and
the contents of LR save area in the second stack frame. In certain scenarios
its possible to have invalid kernel instruction addresses in either of LR or the
second stack frame's LR. In that case, kernel will store the address as zer0.
Hence, its possible to have 2nd or 3rd callstack entry as 0.

As per the current code in match_callstack_filter function, we skip the callstack
check incase we get 0 address. And hence the test case is failing in powerpc.

Fix this issue by updating the check in match_callstack_filter function,
to not skip callstack check if the 2nd or 3rd entry have 0 address
for powerpc.

Result in powerpc after patch changes:

  [command]# ./perf test 81 -vv
   81: kernel lock contention analysis test                            :
   --- start ---
  test child forked, pid 4570
  Testing perf lock record and perf lock contention
  Testing perf lock contention --use-bpf
  [Skip] No BPF support
  Testing perf lock record and perf lock contention at the same time
  Testing perf lock contention --threads
  Testing perf lock contention --lock-addr
  Testing perf lock contention --type-filter (w/ spinlock)
  Testing perf lock contention --lock-filter (w/ tasklist_lock)
  [Skip] Could not find 'tasklist_lock'
  Testing perf lock contention --callstack-filter (w/ unix_stream)
  Testing perf lock contention --callstack-filter with task aggregation
  Testing perf lock contention CSV output
  [Skip] No BPF support
  test child finished with 0
   ---- end ----
  kernel lock contention analysis test: Ok

Fixes: ebab291641 ("perf lock contention: Support filters for different aggregation")
Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Cc: maddy@linux.ibm.com
Cc: atrajeev@linux.vnet.ibm.com
Link: https://lore.kernel.org/r/20231003092113.252380-1-kjain@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:26 +01:00
arch sh: bios: Revive earlyprintk support 2023-11-20 11:59:22 +01:00
block blk-throttle: check for overflow in calculate_bytes_allowed 2023-10-20 18:38:17 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto certs: Break circular dependency when selftest is modular 2023-11-20 11:59:23 +01:00
Documentation dt-bindings: mfd: mt6397: Split out compatible for MediaTek MT6366 PMIC 2023-11-20 11:59:24 +01:00
drivers dmaengine: ti: edma: handle irq_of_parse_and_map() errors 2023-11-20 11:59:26 +01:00
fs f2fs: fix to drop meta_inode's page cache in f2fs_put_super() 2023-11-20 11:59:25 +01:00
include mfd: core: Un-constify mfd_cell.of_reg 2023-11-20 11:59:23 +01:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/kbuf: Allow the full buffer id space for provided buffers 2023-11-20 11:59:11 +01:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel livepatch: Fix missing newline character in klp_resolve_symbols() 2023-11-20 11:59:25 +01:00
lib kunit: test: Fix the possible memory leak in executor_test 2023-11-20 11:59:15 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm vfs: fix readahead(2) on block devices 2023-11-20 11:58:52 +01:00
net ipv6: avoid atomic fragment on GSO packets 2023-11-20 11:59:03 +01:00
rust rust: docs: fix logo replacement 2023-10-19 16:40:00 +02:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n 2023-11-20 11:59:24 +01:00
security apparmor: fix invalid reference on profile->disconnected 2023-11-20 11:59:24 +01:00
sound ASoC: ams-delta.c: use component after check 2023-11-20 11:59:23 +01:00
tools tools/perf: Update call stack check in builtin-lock.c 2023-11-20 11:59:26 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Char/Misc driver fixes for 6.6-final 2023-10-28 07:51:27 -10:00
Makefile Linux 6.6.1 2023-11-08 11:56:25 +01:00
README

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.