From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792790942; b=RxD0xfqRipDZ9tv6hTwCxgCbYkSMHe6npERgHFjCkLSKogGkx8NzT8tFKdlzjgxTSeyz VXNyuHtAVcc04kq5wOk//6DIEdWNM/QXbRO+sKfUG3uIsZ046d1gVr01DsdgtWBzPcMtP 8uLlLgoAmpqfoXBWn5U4AGCmRqz+ud1Z5ohhOEbamdUKGNQ9PLmLhQfRvwjv/BGPnT+ZI GuSTcplT8Fk+W1JvHsG2dsjOKJV9E/amahgJutkyzkjwryH6Lg7mp0Ec3PMHwejBF8EE9 ppjjrKdZ9vTY+vRvB7HSrTuFGOytlEg/v8HImv8gciW+cM2PHoDO7F9HVtXOASIhIDw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792790942; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=SPo5JT16y1DaEMxqlX2cvPgpbj/FzZJAHhXrqtgHuJA=; b=PisjVic8YS8iEIisWSmqUjEbp9gikH3RzcuiL/BtRndytX4UKFAfsCw+kBJz613ognN7 0JC9NLf7hNdcOYyKcQK7JpIMHd23ynFagz8VRk7BNeetp3lW3Ls1HcXlp19QhzPL6sXNd aDOSwk4nGeAbdOHhOR/REzmTcxcccceb2nAARRLd2XajIZuzNRtUmZMJVHh0npSdhpkIH F4Rbd+48AkKdwWZjhvhyjYUCyVEdzMpelm9Zb7DHVtDpqxAh/fA2tSwDmZ4453lU49vms EA8AH2KVFKDIwvoC9ZiP9BEdRLLa7Df0ntP/+TparkHOUq7Zlx+7TIOnTL3uPEC9VqQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HrDUDY5a; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D950606A31B; Fri, 23 Oct 2026 21:29:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HrDUDY5a Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8B5F1F01825; Fri, 23 Oct 2026 21:29:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792790942; bh=SPo5JT16y1DaEMxqlX2cvPgpbj/FzZJAHhXrqtgHuJA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HrDUDY5aj9SM0a/3NOaJ9YsHk3+5IGEa3m+Rkvwx2rIa4v+OTTJKCbh7fH6yIMBED 0toEaHtWlwbgnUf3NXP7gfEHFC4DaM11EBB0NiwfGeoCl15YWcN0Au1w/b0vy27AQl 85J8EtK5nCXBZvuBeZrkB2HwTmmr7qPGHjBpaTRIN/O/SFQsitCMzU++05bW0wOO+7 ZecSyPBhN8g/Diq+Q1UFTK4zTZYJY/7XODqI0GFs/qAleIp9oQNC/KCs7OBZIs/KGS 1IZu6EfJog8RdMlQsyRBFe3zT93NISPFqkC4n4hYvjeUscEDQp4vd3nk+d5zRqH2Gm v3HiBSuV757xw== Date: Fri, 23 Oct 2026 18:28:59 -0300 From: Arnaldo Carvalho de Melo To: Peter Zijlstra Cc: Antoine HURET , Ingo Molnar , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Ravi Bangoria , "linux-perf-users@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "regressions@lists.linux.dev" Subject: Re: [REGRESSION] perf: Rewrite core context handling breaks multiplexed cgroup events Message-ID: References: <20261015111316.GJ4121339@noisy.programming.kicks-ass.net> <20261015132135.GK4121339@noisy.programming.kicks-ass.net> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261015132135.GK4121339@noisy.programming.kicks-ass.net> On Thu, Oct 15, 2026 at 03:21:35PM +0200, Peter Zijlstra wrote: > On Thu, Oct 15, 2026 at 12:30:55PM +0000, Antoine HURET wrote: > > On Thu, Oct 15, 2026 at 11:13 UTC, Peter Zijlstra wrote: > > > /me mutters something about having to go install and learn docker and > > > what's wrong with simple shells scripts that poke about in /cgroup > > > filesystems :-) > > Fair enough, sorry about that! Next time I'll do plain cgroupfs, > > promised :-) > FWIW, it might be useful to extend perf-test with a bunch of cgroup > tests - this one included. AFAICT we have nothing there atm. The more the merrier, so far: acme@phoenix2:~/git/perf-tools-next$ grep -rw cgroup tools/perf/tests/ tools/perf/tests/expand-cgroup.c:#include "cgroup.h" tools/perf/tests/expand-cgroup.c: pr_debug("cgroup name doesn't match:\n"); tools/perf/tests/shell/lib/perf_json_output_lint.py: 'cgroup': lambda x: True, tools/perf/tests/shell/lock_contention.sh: echo "Testing perf lock contention --lock-cgroup" tools/perf/tests/shell/lock_contention.sh: perf lock con -a -b --lock-cgroup -E 1 -q -- ${msg_workload} > /dev/null 2> ${result} tools/perf/tests/shell/lock_contention.sh: echo "Testing perf lock contention --cgroup-filter" tools/perf/tests/shell/lock_contention.sh: perf lock con -a -b --lock-cgroup -E 1 -F wait_total -q \ tools/perf/tests/shell/lock_contention.sh: echo "[Fail] BPF result should have a cgroup result:" "$(cat "${result}")" tools/perf/tests/shell/lock_contention.sh: cgroup=$(cat "${result}" | awk '{ print $3 }') tools/perf/tests/shell/lock_contention.sh: perf lock con -a -b --lock-cgroup -E 1 -G "${cgroup}" -q \ tools/perf/tests/shell/lock_contention.sh: echo "[Fail] BPF result should have a result with cgroup filter:" "$(cat "${cgroup}")" tools/perf/tests/shell/record_bpf_filter.sh: if ! perf record -e task-clock --filter 'cgroup == /' \ tools/perf/tests/shell/record_bpf_filter.sh: -a --all-cgroups --synth=cgroup -o "${perfdata}" true 2> /dev/null tools/perf/tests/shell/record_bpf_filter.sh: echo "Cgroup bpf-filter test [Skipped cgroup not supported]" tools/perf/tests/shell/record_bpf_filter.sh: # 'cgroup' requires PERF_SAMPLE_CGROUP flag tools/perf/tests/shell/record_bpf_filter.sh: if ! perf record -e task-clock --filter 'cgroup == /' \ tools/perf/tests/shell/record_bpf_filter.sh: if ! perf report -i "${perfdata}" -s cgroup -q | grep -q -F '100.00%' tools/perf/tests/shell/record_bpf_filter.sh: echo "Cgroup bpf-filter test [Failed root cgroup does not have 100%]" tools/perf/tests/shell/record.sh: perf script -i "${perfdata}" -F cgroup 2>/dev/null | grep -q -v "unknown" tools/perf/tests/shell/record.sh: -aB --synth=cgroup --all-cgroups || ret=$? tools/perf/tests/shell/trace_summary.sh:# summary only for system wide - cgroup summary mode with BPF tools/perf/tests/shell/trace_summary.sh:test_perf_trace "-as --summary-mode=cgroup --bpf-summary" tools/perf/tests/shell/trace_summary.sh:# summary with normal output for system wide - cgroup summary mode with BPF tools/perf/tests/shell/trace_summary.sh:test_perf_trace "-aS --summary-mode=cgroup --bpf-summary" tools/perf/tests/shell/stat_bpf_counters_cgrp.sh:# perf stat --bpf-counters --for-each-cgroup test (no_mlock) tools/perf/tests/shell/stat_bpf_counters_cgrp.sh:# skip if --bpf-counters --for-each-cgroup is not supported tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: if ! perf stat -a --bpf-counters --for-each-cgroup / true > /dev/null 2>&1; then tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: echo "Skipping: --bpf-counters --for-each-cgroup not supported" tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: perf --no-pager stat -a --bpf-counters --for-each-cgroup / true || true tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: if [ -d /sys/fs/cgroup/system.slice ] && [ -d /sys/fs/cgroup/user.slice ]; then tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: find_cgroups_self_cgrp=$(grep perf_event /proc/self/cgroup | cut -d: -f3) tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: # cgroup v2 doesn't specify perf_event tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: find_cgroups_self_cgrp=$(grep ^0: /proc/self/cgroup | cut -d: -f3) tools/perf/tests/shell/stat_bpf_counters_cgrp.sh:# As cgroup events are cpu-wide, we cannot simply compare the result. tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: check_system_wide_counted_output=$(perf stat -a --bpf-counters --for-each-cgroup ${test_cgroups} -e cpu-clock -x, sleep 1 2>&1) tools/perf/tests/shell/stat_bpf_counters_cgrp.sh: expand_output=$(perf stat -a -x, --bpf-counters --for-each-cgroup / true 2>&1 | wc -l) tools/perf/tests/shell/stat_metrics_cgrp.sh:# perf stat metrics --for-each-cgroup test (no_mlock) tools/perf/tests/shell/stat_metrics_cgrp.sh: if [ -d /sys/fs/cgroup/system.slice ] && [ -d /sys/fs/cgroup/user.slice ] tools/perf/tests/shell/stat_metrics_cgrp.sh: find_cgroups_self_cgrp=$(grep perf_event /proc/self/cgroup | cut -d: -f3) tools/perf/tests/shell/stat_metrics_cgrp.sh: # cgroup v2 doesn't specify perf_event tools/perf/tests/shell/stat_metrics_cgrp.sh: find_cgroups_self_cgrp=$(grep ^0: /proc/self/cgroup | cut -d: -f3) tools/perf/tests/shell/stat_metrics_cgrp.sh:# Check if metric is reported for each cgroup tools/perf/tests/shell/stat_metrics_cgrp.sh: --for-each-cgroup "${test_cgroups}" \ tools/perf/tests/shell/stat_metrics_cgrp.sh: # Find metric lines for this cgroup tools/perf/tests/shell/stat_metrics_cgrp.sh: /) # The root cgroup, leave unchanged. tools/perf/tests/shell/stat_metrics_cgrp.sh: # We use exact cgroup match with surrounding commas tools/perf/tests/shell/stat_metrics_cgrp.sh: echo "FAIL: No metric lines found for cgroup '${cgrp}'" tools/perf/tests/shell/stat_metrics_cgrp.sh: log_verbose "Enforcing metric check for cgroup '${cgrp}' \ tools/perf/tests/shell/stat_metrics_cgrp.sh:for cgroup '${cgrp}'" tools/perf/tests/shell/stat_metrics_cgrp.sh: echo "FAIL: Empty metric value for cgroup '${cgrp}'" tools/perf/tests/shell/stat_metrics_cgrp.sh: log_verbose "Skipping metric check for cgroup '${cgrp}' \ tools/perf/tests/shell/stat_metrics_cgrp.sh:if perf stat -a --bpf-counters --for-each-cgroup / true > /dev/null 2>&1 tools/perf/tests/sample-parsing.c: COMP(cgroup); tools/perf/tests/sample-parsing.c: .cgroup = 114, tools/perf/tests/Build:perf-test-y += expand-cgroup.o acme@phoenix2:~/git/perf-tools-next$ - Arnaldo