From patchwork Thu Dec 29 20:41:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13083821 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 302AAC3DA79 for ; Thu, 29 Dec 2022 20:44:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234175AbiL2UoE (ORCPT ); Thu, 29 Dec 2022 15:44:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234182AbiL2Ung (ORCPT ); Thu, 29 Dec 2022 15:43:36 -0500 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B68A18387; Thu, 29 Dec 2022 12:41:07 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id jn22so19944749plb.13; Thu, 29 Dec 2022 12:41:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=5+7CR58SPvhZSbvxiF3pO3ff849ICg9QIOe5C8t8+9o=; b=XrHqS0Trcpa4Hn59n/py1EEYcBPf8OPeyq9pDLIzTLmc/xTM376UuDQEjqJbvCAU0O pORf3gMmzYLe6R6hrjbjjIGN5qmJV4O2/BKkPVmwM1z7ByVSh2bcGKH43sI0Gobopw16 DQsgYebDdH0VDoKCNIrLtkyH+2Q7Um0LAte1tKWw4mMaVoHkVzs7TYSsDcypOIyKxMsc s+mhNPoFfCm4+dmMbj0DhoNlvqk+b03iA2p6FWQIRkkzMk0/yqOdxHqbOxN0MLvyMgfM 0mq1aQp1ceQpBx+NBXusEz9OjzyOZSHvnCd5XwR2EQi1iHi0LMRMHORnfmfF6weed7il PDkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=5+7CR58SPvhZSbvxiF3pO3ff849ICg9QIOe5C8t8+9o=; b=Os/5xXIiOKmcwQRYrYcs8XXmF5+63gcNt4j34xkT3kzUmfvoMVlrbpLJVEnsUKwq/V IlRCIPlNAQDi42qFkwumrIcO/98y0ld6wy4Syp0bFGUyVzK45fb/4tjrS/i84n8VHxxB us8rcqySRCbsRpI2biI6XsDis2IlRBTjolZg9Ba83J9H6yp2dM9rKeIolgpYgSykBwcc 38cUFzHuel3HFUSX7SAkv3hxXSAOVuDYKnYGJrdeMpck8ODMvS8FLALzw2FYBVkLDV/K IJqX5DhdJ5ccZWZ2jCgTRtFr16d3UfkBhu48s3NcT8Io3LQp+YHuP09Ymx7WRVTZ6wvP N8GA== X-Gm-Message-State: AFqh2kq4RAeXIjVzzgkKUNRwzAxKx/I9SoYe2rdmmvteUHXA6tCPBtAz /jYWrZypjptcSYsOlqyPnTVm1iTcq2CyCw== X-Google-Smtp-Source: AMrXdXuamyUtbCEYIAxU87Kwz446hazHbxIhbYjn3tc/7GQegmmiAhB4yDaqhA2edKHhkxWXcOAjag== X-Received: by 2002:a17:903:31d5:b0:191:4539:d2c1 with SMTP id v21-20020a17090331d500b001914539d2c1mr30581759ple.47.1672346466671; Thu, 29 Dec 2022 12:41:06 -0800 (PST) Received: from balhae.hsd1.ca.comcast.net ([2601:647:6780:ff0:d74d:9c28:5a9d:f5b9]) by smtp.gmail.com with ESMTPSA id q15-20020a17090311cf00b001754fa42065sm13413824plh.143.2022.12.29.12.41.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Dec 2022 12:41:06 -0800 (PST) Sender: Namhyung Kim From: Namhyung Kim To: Peter Zijlstra , Ingo Molnar Cc: LKML , Arnaldo Carvalho de Melo , Jiri Olsa , Kan Liang , Ravi Bangoria , bpf@vger.kernel.org Subject: [PATCH 3/3] perf/core: Save calculated sample data size Date: Thu, 29 Dec 2022 12:41:01 -0800 Message-Id: <20221229204101.1099430-3-namhyung@kernel.org> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog In-Reply-To: <20221229204101.1099430-1-namhyung@kernel.org> References: <20221229204101.1099430-1-namhyung@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org To avoid duplicate work in perf_prepare_sample(), save the final header size in data->saved_size. It's initialized to 0 and set to an actual value at the end of perf_prepare_sample(). If it sees a non-zero value that means it's the second time of the call and it knows the sample data is populated already. So update the header size with the data->saved_size and bail out. Signed-off-by: Namhyung Kim --- include/linux/perf_event.h | 2 ++ kernel/events/core.c | 11 +++++++++++ 2 files changed, 13 insertions(+) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index dd565306f479..ccde631a0cb4 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1103,6 +1103,7 @@ struct perf_sample_data { */ u64 sample_flags; u64 period; + u64 saved_size; /* * Fields commonly set by __perf_event_header__init_id(), @@ -1158,6 +1159,7 @@ static inline void perf_sample_data_init(struct perf_sample_data *data, /* remaining struct members initialized in perf_prepare_sample() */ data->sample_flags = PERF_SAMPLE_PERIOD; data->period = period; + data->saved_size = 0; if (addr) { data->addr = addr; diff --git a/kernel/events/core.c b/kernel/events/core.c index 70bff8a04583..dac4d76e2877 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7575,6 +7575,15 @@ void perf_prepare_sample(struct perf_event_header *header, header->misc = 0; header->misc |= perf_misc_flags(regs); + /* + * If it called perf_prepare_sample() already, it set the all data fields + * and recorded the final size to data->saved_size. + */ + if (data->saved_size) { + header->size = data->saved_size; + return; + } + /* * Clear the sample flags that have already been done by the * PMU driver. @@ -7796,6 +7805,8 @@ void perf_prepare_sample(struct perf_event_header *header, * do here next. */ WARN_ON_ONCE(header->size & 7); + + data->saved_size = header->size; } static __always_inline int