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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 59ED7C433F5 for ; Tue, 28 Aug 2018 08:57:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 154082089E for ; Tue, 28 Aug 2018 08:57:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 154082089E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1727540AbeH1Mro (ORCPT ); Tue, 28 Aug 2018 08:47:44 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50534 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726954AbeH1Mro (ORCPT ); Tue, 28 Aug 2018 08:47:44 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 216B28E67D; Tue, 28 Aug 2018 08:57:05 +0000 (UTC) Received: from krava (unknown [10.43.17.209]) by smtp.corp.redhat.com (Postfix) with SMTP id D2CEF2026E18; Tue, 28 Aug 2018 08:57:03 +0000 (UTC) Date: Tue, 28 Aug 2018 10:57:03 +0200 From: Jiri Olsa To: Alexey Budankov Cc: Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel Subject: Re: [PATCH v3 2/2]: perf record: enable asynchronous trace writing Message-ID: <20180828085703.GG23727@krava> References: <6f83f9cd-263e-b073-487f-4c7570105a7d@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6f83f9cd-263e-b073-487f-4c7570105a7d@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 28 Aug 2018 08:57:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 28 Aug 2018 08:57:05 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jolsa@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 27, 2018 at 09:16:55PM +0300, Alexey Budankov wrote: SNIP > + int trace_fd = rec->session->data->file.fd; > + struct aiocb **mmap_aio = rec->evlist->mmap_aio; > + int mmap_aio_size = 0; > + off_t off; > > if (!evlist) > return 0; > @@ -528,14 +632,17 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli > if (overwrite && evlist->bkw_mmap_state != BKW_MMAP_DATA_PENDING) > return 0; > > + off = lseek(trace_fd, 0, SEEK_CUR); > + > for (i = 0; i < evlist->nr_mmaps; i++) { > struct auxtrace_mmap *mm = &maps[i].auxtrace_mmap; > > if (maps[i].base) { > - if (perf_mmap__push(&maps[i], rec, record__pushfn) != 0) { > - rc = -1; > + rc = perf_mmap__push(&maps[i], rec, record__pushfn, &off); > + if (rc < 0) > goto out; > - } > + else if (rc > 0) > + mmap_aio[mmap_aio_size++] = &maps[i].cblock; I understand the purpose of mmap_aio array, but I don't see a reason to fill it in every time we call record__mmap_read_evlist the way I see it, when 'pushing the data' it's either all or nothing, if there's an error in pushing one map, we bail out completely.. so the mmap_aio array could be preallocated (it is now) and pre-filled with cblock pointers that would probably ease up the reference counting I mentioned in the previous email thanks, jirka