From nobody Sun Feb 8 11:41:03 2026 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 553E855E57 for ; Fri, 8 Mar 2024 12:13:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.66 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709900015; cv=none; b=NBFxoRl8WO7YeQiTRpAJqk+WitD12H+EB1EGNznGIA0mH5fkkgLfqgYmouofGOUnBeRtLGU74N+uRsgtMtd9Ekvk65BpebcPo6kzxVpR4Pi5NcW/ECtzjCaIZrtSLmCtKrslBmao+K6CzpEUrMsFUGZaVJNkQTj0i0WadW60Sb8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709900015; c=relaxed/simple; bh=o0MIa9u9Hqk3ZI02Q4Ut0uAnmSuanvs+Ylycd/Utd04=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=X1cJXgz7E7hOTgrwlpoQ08TwHWPI0nLWHr3+eK2BGISGy6KPMFGnQd/vC7Ch3JJt2YqAsuLIHBrYax7OwI++rVV7RlwxKc37AoKLwPZb2s1iJd9Nu2EpGDjPgGN4pe2Y7f9jPENw6W31e8ZoEqTmnZ2B+AliQq67b1QElXkMc4A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.net; spf=pass smtp.mailfrom=posteo.net; dkim=pass (2048-bit key) header.d=posteo.net header.i=@posteo.net header.b=XW/ufEFY; arc=none smtp.client-ip=185.67.36.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.net header.i=@posteo.net header.b="XW/ufEFY" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id C6D4D240103 for ; Fri, 8 Mar 2024 13:04:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1709899492; bh=o0MIa9u9Hqk3ZI02Q4Ut0uAnmSuanvs+Ylycd/Utd04=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version: Content-Transfer-Encoding:From; b=XW/ufEFYmNghRO9/dJpnthQiWG7F4dM+r84VMWzKXpuhutstXjOfZcZVwq8eD5q01 t4A8Ln8tyESKKT1F6ZDp2vvod4+GJ7xKCv/k3vNStrYVmHZGYm+8mPempnvYqOJvsy IO9XVYJdX5DGKgBSmWI1didokQ4Zwy6/Yw8gwX+WhVYHBIzKqvPi6WSiMymB3u5izt Yf8NnyPMgTePJtbcEKA4zif/FT+3mHfKD72jAPe46dZ/iqkTenldUYejPs87ZQKjMS l5nLQnXLx/7SfOCKQZl+LRa93RQa0mTE6wLfu1jmAoiwZ5HB6zR5xp54LSrOd1Qs5a PYDPrkir/LokA== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4TrlGQ6hCkz6tm4; Fri, 8 Mar 2024 13:04:46 +0100 (CET) From: Anne Macedo To: Arnaldo Carvalho de Melo , Namhyung Kim Cc: Anne Macedo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v0] perf lock contention: skip traceiter functions Date: Fri, 8 Mar 2024 12:03:31 +0000 Message-Id: <20240308120332.372810-1-retpolanne@posteo.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The perf lock contention program currently shows the caller of the locks as __traceiter_contention_begin+0x??. This caller can be ignored, as it is from the traceiter itself. Instead, it should show the real callers for the locks. When fiddling with the --stack-skip parameter, the actual callers for the locks start to show up. However, just ignore the __traceiter_contention_begin and the __traceiter_contention_end symbols so the actual callers will show up. Before this patch is applied: sudo perf lock con -a -b -- sleep 3 contended total wait max wait avg wait type caller 8 2.33 s 2.28 s 291.18 ms rwlock:W __traceite= r_contention_begin+0x44 4 2.33 s 2.28 s 582.35 ms rwlock:W __traceite= r_contention_begin+0x44 7 140.30 ms 46.77 ms 20.04 ms rwlock:W __traceite= r_contention_begin+0x44 2 63.35 ms 33.76 ms 31.68 ms mutex trace_cont= ention_begin+0x84 2 46.74 ms 46.73 ms 23.37 ms rwlock:W __traceite= r_contention_begin+0x44 1 13.54 us 13.54 us 13.54 us mutex trace_cont= ention_begin+0x84 1 3.67 us 3.67 us 3.67 us rwsem:R __traceite= r_contention_begin+0x44 Before this patch is applied - using --stack-skip 5 sudo perf lock con --stack-skip 5 -a -b -- sleep 3 contended total wait max wait avg wait type caller 2 2.24 s 2.24 s 1.12 s rwlock:W do_epoll_w= ait+0x5a0 4 1.65 s 824.21 ms 412.08 ms rwlock:W do_exit+0x= 338 2 824.35 ms 824.29 ms 412.17 ms spinlock get_signal= +0x108 2 824.14 ms 824.14 ms 412.07 ms rwlock:W release_ta= sk+0x68 1 25.22 ms 25.22 ms 25.22 ms mutex cgroup_kn_= lock_live+0x58 1 24.71 us 24.71 us 24.71 us spinlock do_exit+0x= 44 1 22.04 us 22.04 us 22.04 us rwsem:R lock_mm_an= d_find_vma+0xb0 After this patch is applied: sudo ./perf lock con -a -b -- sleep 3 contended total wait max wait avg wait type caller 6 5.27 s 1.76 s 878.55 ms rwlock:W release_ta= sk+0x68 2 2.99 s 2.99 s 1.50 s spinlock do_send_si= g_info+0x3c 2 1.77 s 1.77 s 884.39 ms spinlock sigprocmas= k+0x98 2 1.76 s 1.76 s 878.56 ms rwlock:W do_exit+0x= 338 2 1.76 s 1.76 s 878.55 ms rwlock:W release_ta= sk+0x68 5 1.76 s 1.76 s 351.41 ms rwlock:W do_exit+0x= 338 1 48.10 ms 48.10 ms 48.10 ms mutex trace_cont= ention_begin+0x84 4 257.80 us 119.34 us 64.45 us spinlock get_signal= +0x108 1 9.33 us 9.33 us 9.33 us rwlock:W do_exit+0x= 338 Signed-off-by: Anne Macedo --- tools/perf/util/machine.c | 10 ++++++++++ tools/perf/util/machine.h | 2 +- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 527517db3182..8e729167c1aa 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -3266,6 +3266,12 @@ bool machine__is_lock_function(struct machine *machi= ne, u64 addr) =20 sym =3D machine__find_kernel_symbol_by_name(machine, "__lock_text_end", = &kmap); machine->lock.text_end =3D map__unmap_ip(kmap, sym->start); + + sym =3D machine__find_kernel_symbol_by_name(machine, "__traceiter_conten= tion_begin", &kmap); + machine->traceiter.text_start =3D map__unmap_ip(kmap, sym->start); + + sym =3D machine__find_kernel_symbol_by_name(machine, "__traceiter_conten= tion_end", &kmap); + machine->traceiter.text_end =3D map__unmap_ip(kmap, sym->start); } =20 /* failed to get kernel symbols */ @@ -3280,5 +3286,9 @@ bool machine__is_lock_function(struct machine *machin= e, u64 addr) if (machine->lock.text_start <=3D addr && addr < machine->lock.text_end) return true; =20 + /* traceiter functions are in traceiter text section */ + if (machine->traceiter.text_start <=3D addr && addr < machine->traceiter.= text_end) + return true; + return false; } diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index e28c787616fe..ec51e9b080b9 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -49,7 +49,7 @@ struct machine { struct { u64 text_start; u64 text_end; - } sched, lock; + } sched, lock, traceiter; pid_t *current_tid; size_t current_tid_sz; union { /* Tool specific area */ --=20 2.39.2