From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EF7BC65C20 for ; Mon, 8 Oct 2018 12:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4239920858 for ; Mon, 8 Oct 2018 12:24:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4239920858 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726569AbeJHTgD (ORCPT ); Mon, 8 Oct 2018 15:36:03 -0400 Received: from mga03.intel.com ([134.134.136.65]:37249 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725857AbeJHTgD (ORCPT ); Mon, 8 Oct 2018 15:36:03 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Oct 2018 05:24:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,356,1534834800"; d="scan'208";a="263839093" Received: from linux.intel.com ([10.54.29.200]) by orsmga005.jf.intel.com with ESMTP; 08 Oct 2018 05:24:34 -0700 Received: from [10.125.251.251] (abudanko-mobl.ccr.corp.intel.com [10.125.251.251]) by linux.intel.com (Postfix) with ESMTP id C2F355801E6; Mon, 8 Oct 2018 05:24:32 -0700 (PDT) Subject: Re: [PATCH v11 2/3]: perf record: enable asynchronous trace writing To: Jiri Olsa Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel References: <7d42aa80-8e69-44e4-b963-e8ef89df2099@linux.intel.com> <31b0ae5f-e1b5-4255-11af-46c8ebe8e2be@linux.intel.com> <20181008105254.GG17270@krava> From: Alexey Budankov Organization: Intel Corp. Message-ID: Date: Mon, 8 Oct 2018 15:24:31 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181008105254.GG17270@krava> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 08.10.2018 13:52, Jiri Olsa wrote: > On Mon, Oct 08, 2018 at 09:17:11AM +0300, Alexey Budankov wrote: >> +#ifdef HAVE_AIO_SUPPORT >> + off = lseek(trace_fd, 0, SEEK_CUR); >> +#endif > > I'm still little puzzled why we need to do this, > when the aio write takes the offset value, but pwrite() syscall [1] which is the base for aio_write() doesn't advance file pos value so it requires to be calculated and updated by callers of aio_write() API. > please provide some aio_.. function for this Accepted. > > >> for (i = 0; i < evlist->nr_mmaps; i++) { >> struct perf_mmap *map = &maps[i]; >> >> if (map->base) { >> - if (perf_mmap__push(map, rec, record__pushfn) != 0) { >> - rc = -1; >> - goto out; >> +#ifdef HAVE_AIO_SUPPORT >> + if (!rec->opts.nr_cblocks) { >> +#endif >> + if (perf_mmap__push(map, rec, record__pushfn) != 0) { >> + rc = -1; >> + goto out; >> + } >> +#ifdef HAVE_AIO_SUPPORT >> + } else { >> + /* >> + * Call record__aio_sync() to wait till map->data buffer >> + * becomes available after previous aio write request. >> + */ >> + record__aio_sync(map); >> + if (perf_mmap__aio_push(map, rec, record__aio_pushfn, &off) != 0) { >> + lseek(trace_fd, off, SEEK_SET); >> + rc = -1; >> + goto out; >> + } >> } >> +#endif >> } >> >> if (map->auxtrace_mmap.base && !rec->opts.auxtrace_snapshot_mode && >> @@ -547,7 +694,9 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli >> goto out; >> } >> } >> - >> +#ifdef HAVE_AIO_SUPPORT >> + lseek(trace_fd, off, SEEK_SET); >> +#endif > > ditto Accepted. Thanks, Alexey > > thanks, > jirka > [1] http://man7.org/linux/man-pages/man2/pread.2.html