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 ECF7925745B; Wed, 19 Feb 2025 21:54:11 +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=1740002052; cv=none; b=YGBWfV11RUcbk2/DqUofNBJeo/h0/wgv5JBdom5oq09mY9bxtlS6rrP0TD/SMFpl3O+q6Gv1/6s+xXWHuR+oIQ75PePyhcijRetZT9nHNuBkr4iR1frDiF0na0oLwh5/yTyd68h9WPW9EixMLAAlW0Wnh6nZByJJQTe24OV8gxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740002052; c=relaxed/simple; bh=kyMwcNXN8YDzje5Qw7hFShfVLdsBWRKu6y0nbvuD0t0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QOJkW4z+rXQMNKPYGOcogVYFU3hvPD2dgAv7O/4Fvqvn+NB32hVS70mZ58npeix/PT2OC0MuZynJizZvRFwamnlNxoy7Q4FlKfrvN9a93Ta0hRRart2ooukoInX00j/IGReDa8j/t1DUv9Dtcgj4Ie88L7waaKWsPpmV090WqXU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QPVIrJ/n; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QPVIrJ/n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3D38C4CED1; Wed, 19 Feb 2025 21:54:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740002051; bh=kyMwcNXN8YDzje5Qw7hFShfVLdsBWRKu6y0nbvuD0t0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QPVIrJ/nLuVCPSjzrSNllgcZHE8N1cC/lrnmSAt7Y1Nc+VVn6N1zxy8QNAHIksvML kq7WlSXrkkUxQzSOJGB5Ht/BKBr8SwY9LcoTK4dHgvsOked0XooXXr7ADbxSXLYzsE iZAhJanZOKW93mk7MoMVkB0dooFIIqQcmNjIcIQEpljODmuI96/TuHY9gm2WPy9rY7 nKh0pfcs4OqixLsyRyMmQqoFD29sLSFDqAPExeHYKqvXR8NFWM4/AigkQJyZxm8ev5 MNbnXCMl83xV7Jo7NkY+cYLxDqUGtnAdYJvYWJalwUCyQof7hmC8VzWAgwgxeskfZD ifLEI+pqPnNiw== Date: Wed, 19 Feb 2025 13:54:09 -0800 From: Namhyung Kim To: Ian Rogers Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Adrian Hunter , Kan Liang , Sam James , Jesper Juhl , James Clark , Zhongqiu Han , Yicong Yang , Thomas Richter , Michael Petlan , Veronika Molnarova , Anne Macedo , Dominique Martinet , Jean-Philippe Romain , Junhao He , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Krzysztof =?utf-8?Q?=C5=81opatowski?= Subject: Re: [PATCH v2 0/7] Add io_dir to avoid memory overhead from opendir Message-ID: References: <20250207232452.994822-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250207232452.994822-1-irogers@google.com> On Fri, Feb 07, 2025 at 03:24:41PM -0800, Ian Rogers wrote: > glibc's opendir allocates a minimum of 32kb, when called recursively > for a directory tree the memory consumption can add up - nearly 300kb > during perf start-up when processing modules. Add a stack allocated > variant of readdir sized a little more than 1kb > > v2: Remove the feature test and always use a perf supplied getdents64 > to workaround an Alpine Linux issue in v1: > https://lore.kernel.org/lkml/20231207050433.1426834-1-irogers@google.com/ > As suggested by Krzysztof Łopatowski > who also pointed to the perf > trace performance improvements in start-up time eliminating stat > calls can achieve: > https://lore.kernel.org/lkml/20250206113314.335376-2-krzysztof.m.lopatowski@gmail.com/ Let me pick up Krzysztof's patch first. Thanks, Namhyung > Convert parse-events and hwmon_pmu to use io_dir. > v1: This was previously part of the memory saving change set: > https://lore.kernel.org/lkml/20231127220902.1315692-1-irogers@google.com/ > It is separated here and a feature check and syscall workaround > for missing getdents64 added. > > Ian Rogers (7): > tools lib api: Add io_dir an allocation free readdir alternative > perf maps: Switch modules tree walk to io_dir__readdir > perf pmu: Switch to io_dir__readdir > perf header: Switch mem topology to io_dir__readdir > perf events: Remove scandir in thread synthesis > perf parse-events: Switch tracepoints to io_dir__readdir > perf hwmon_pmu: Switch event discovery to io_dir__readdir > > tools/lib/api/Makefile | 2 +- > tools/lib/api/io_dir.h | 91 ++++++++++++++++++++++++++++++ > tools/perf/util/header.c | 31 +++++----- > tools/perf/util/hwmon_pmu.c | 42 ++++++-------- > tools/perf/util/machine.c | 19 +++---- > tools/perf/util/parse-events.c | 32 ++++++----- > tools/perf/util/pmu.c | 46 +++++++-------- > tools/perf/util/pmus.c | 30 ++++------ > tools/perf/util/synthetic-events.c | 22 ++++---- > 9 files changed, 194 insertions(+), 121 deletions(-) > create mode 100644 tools/lib/api/io_dir.h > > -- > 2.48.1.502.g6dc24dfdaf-goog >