From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3ED7C29553A; Wed, 30 Apr 2025 20:01:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746043266; cv=none; b=qt9I+EvUInaHqkHFmirjUlb3g2hJ331579CtGVN6Faf767AYC30MzvNIqvH1Cy9BQWgrhXLq2MfZm6ITr5Ybzq/NbyXDcqSykiix9d0Knd5ZGM0+UUtkvOjCUgq48xMmIWS/XhWjlwlGrnnM+VBD3VhzLaTdPzhehv4OuA6pT3k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746043266; c=relaxed/simple; bh=VcxOh3mOnIXjHWm2qqnllSh0bi7tu4jE843+0n9nFa4=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=ae1/d+DZcbvbhI3SDrrXSfxg20045AJ1ab7tGB0zZi0vtk6NhZqvIPcfoQ7ZXPOLmWRe/rXd8+AZEb7gDmlmQcjLwU5K46qR/ond1zW//2ml5fJZ+xVSCmE02O7ko9jJ5ApV+1nbaerng8WeBC07qPOqhyQ8qM13gNg2dGqqsPM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09658C4AF19; Wed, 30 Apr 2025 20:01:06 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uADcE-00000001dV7-1P96; Wed, 30 Apr 2025 16:01:10 -0400 Message-ID: <20250430200110.182678717@goodmis.org> User-Agent: quilt/0.68 Date: Wed, 30 Apr 2025 15:58:02 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Josh Poimboeuf , x86@kernel.org, Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Indu Bhagat , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org, Jordan Rome , Sam James , Andrii Nakryiko , Jens Remus , Florian Weimer , Andy Lutomirski , Weinan Liu , Blake Jones , Beau Belgrave , "Jose E. Marchesi" , Alexander Aring Subject: [PATCH v7 16/18] perf record: Enable defer_callchain for user callchains References: <20250430195746.827125963@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Namhyung Kim And add the missing feature detection logic to clear the flag on old kernels. $ perf record -g -vv true ... ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) size 136 config 0 (PERF_COUNT_HW_CPU_CYCLES) { sample_period, sample_freq } 4000 sample_type IP|TID|TIME|CALLCHAIN|PERIOD read_format ID|LOST disabled 1 inherit 1 mmap 1 comm 1 freq 1 enable_on_exec 1 task 1 sample_id_all 1 mmap2 1 comm_exec 1 ksymbol 1 bpf_event 1 defer_callchain 1 ------------------------------------------------------------ sys_perf_event_open: pid 162755 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open failed, error -22 switching off deferred callchain support Signed-off-by: Namhyung Kim Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) --- tools/perf/util/evsel.c | 24 ++++++++++++++++++++++++ tools/perf/util/evsel.h | 1 + 2 files changed, 25 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index b872236a2413..669e585dedee 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1076,6 +1076,14 @@ static void __evsel__config_callchain(struct evsel *evsel, struct record_opts *o } } + if (param->record_mode == CALLCHAIN_FP && !attr->exclude_callchain_user) { + /* + * Enable deferred callchains optimistically. It'll be switched + * off later if the kernel doesn't support it. + */ + attr->defer_callchain = 1; + } + if (function) { pr_info("Disabling user space callchains for function trace event.\n"); attr->exclude_callchain_user = 1; @@ -2123,6 +2131,8 @@ static int __evsel__prepare_open(struct evsel *evsel, struct perf_cpu_map *cpus, static void evsel__disable_missing_features(struct evsel *evsel) { + if (perf_missing_features.defer_callchain) + evsel->core.attr.defer_callchain = 0; if (perf_missing_features.inherit_sample_read && evsel->core.attr.inherit && (evsel->core.attr.sample_type & PERF_SAMPLE_READ)) evsel->core.attr.inherit = 0; @@ -2397,6 +2407,15 @@ static bool evsel__detect_missing_features(struct evsel *evsel, struct perf_cpu /* Please add new feature detection here. */ + attr.defer_callchain = true; + attr.sample_type = PERF_SAMPLE_CALLCHAIN; + if (has_attr_feature(&attr, /*flags=*/0)) + goto found; + perf_missing_features.defer_callchain = true; + pr_debug2("switching off deferred callchain support\n"); + attr.defer_callchain = false; + attr.sample_type = 0; + attr.inherit = true; attr.sample_type = PERF_SAMPLE_READ; if (has_attr_feature(&attr, /*flags=*/0)) @@ -2508,6 +2527,11 @@ static bool evsel__detect_missing_features(struct evsel *evsel, struct perf_cpu errno = old_errno; check: + if (evsel->core.attr.defer_callchain && + evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN && + perf_missing_features.defer_callchain) + return true; + if (evsel->core.attr.inherit && (evsel->core.attr.sample_type & PERF_SAMPLE_READ) && perf_missing_features.inherit_sample_read) diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index aae431d63d64..7ded99c774c7 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -211,6 +211,7 @@ struct perf_missing_features { bool branch_counters; bool aux_action; bool inherit_sample_read; + bool defer_callchain; }; extern struct perf_missing_features perf_missing_features; -- 2.47.2