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 EFEFA1AE875; Tue, 22 Apr 2025 19:05:57 +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=1745348758; cv=none; b=eQHUlcu/gB5OmevoaT+I86t8be2BY7ssgPsWp9DcOPJF7rVAJSrP0xUUvKVTMljIentSmNumEDSj7zcDW3YAFiMTwuG20NUZw9FzWNsSN/eqZmlOzzXP9oR4zfd6aV2zU8nehPQFZGGmDenIDh7UuzsZ/Cd9yX9RvBW3cl+wYzI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745348758; c=relaxed/simple; bh=ox3n7vqTRmaUjl5zlNSMs/7SpZ+Hew6klvq5n7FcVKY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tfgwsppoSIV/c0V6cn+b7tWe/pT3Qmhq+jkZOw+zfsyTMc3CREpU0nvRTT6BfjrFf2in1XXRsJt7uSWbZpkPqmy0GFlGM/Jh5pe96yiMH0vDtApcGayPhagl83T/tN0jcFn1ZpmBcbdw9ddSzHl6J4PD6dAn2F31xqhlZRQlh34= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G470giim; 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="G470giim" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFA95C4CEEB; Tue, 22 Apr 2025 19:05:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745348757; bh=ox3n7vqTRmaUjl5zlNSMs/7SpZ+Hew6klvq5n7FcVKY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G470giimj570BGdmzoDFkKc9naA3AhDoFLWk4AK+FuKz5IXJkbOU8UPsnD0/JBcMU uuS6niscYbR2kK/3GncoczZ+FFwL0lyl+AqPDRiOr/T1v8RkPhdkLQYjf5YMCP/gft g1Hz80742PRImiE2f3CZcP2tMMQ0P3RBs9+GGKeQbI6wTJUXZXzOuEaZLGPfl17Nem GxQ+zZctAEzH45GpQL74v96XmeJQb/sfev8MBgl3HbTvoLuSARUwd0Bf1zONtOCZqS xw3bjQMK1Z/UTrC4Kr7lqHQ7FgLEUN1bGfHmAx50AHjhFrCdJ3daBtDDD6ijT4dgY1 UQFdIHANME10w== Date: Tue, 22 Apr 2025 12:05:55 -0700 From: Namhyung Kim To: Jiri Olsa Cc: Tao Chen , andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH bpf-next] libbpf: remove sample_period init in perf_buffer Message-ID: References: <20250422091558.2834622-1-chen.dylane@linux.dev> 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 In-Reply-To: Hello, On Tue, Apr 22, 2025 at 03:43:43PM +0200, Jiri Olsa wrote: > On Tue, Apr 22, 2025 at 05:15:58PM +0800, Tao Chen wrote: > > It seems that sample_period no used in perf buffer, actually only > > wakeup_events valid about events aggregation for wakeup. So remove > > it to avoid causing confusion. > > I don't see too much confusion in keeping it, but I think it > should be safe to remove it > > PERF_COUNT_SW_BPF_OUTPUT is "trigered" by bpf_perf_event_output, > AFAICS there's no path checking on sample_period for this event > used in context of perf_buffer__new, Namhyung, thoughts? It seems to be ok to call mmap(2) for non-sampling events. Acked-by: Namhyung Kim Thanks, Namhyung > > > > > Fixes: fb84b8224655 ("libbpf: add perf buffer API") > > Signed-off-by: Tao Chen > > --- > > tools/lib/bpf/libbpf.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > > index 194809da5172..1830e3c011a5 100644 > > --- a/tools/lib/bpf/libbpf.c > > +++ b/tools/lib/bpf/libbpf.c > > @@ -13306,7 +13306,6 @@ struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt, > > attr.config = PERF_COUNT_SW_BPF_OUTPUT; > > attr.type = PERF_TYPE_SOFTWARE; > > attr.sample_type = PERF_SAMPLE_RAW; > > - attr.sample_period = sample_period; > > attr.wakeup_events = sample_period; > > > > p.attr = &attr; > > -- > > 2.43.0 > >