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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 83C54C433DF for ; Mon, 15 Jun 2020 17:38:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AE6420739 for ; Mon, 15 Jun 2020 17:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731183AbgFORiW (ORCPT ); Mon, 15 Jun 2020 13:38:22 -0400 Received: from mga09.intel.com ([134.134.136.24]:13207 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729124AbgFORiV (ORCPT ); Mon, 15 Jun 2020 13:38:21 -0400 IronPort-SDR: nHhK65yffsU9gW0m9IIj4JnAgo1nagymqyCoAyWFZe2wx8HvfTefVbBftu9KDOFLY2HPO+uDsK uWPLN3XA+qCA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2020 10:38:07 -0700 IronPort-SDR: 77XvAN7QtL7FXnvb3ofpXsoTPQGFAA6qjNSoP7pFM3iFnSGOv7JGa96KD7ugNJGDOL+FYE3CYh RqM7ET9XIQLw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,515,1583222400"; d="scan'208";a="351438005" Received: from linux.intel.com ([10.54.29.200]) by orsmga001.jf.intel.com with ESMTP; 15 Jun 2020 10:38:07 -0700 Received: from [10.249.225.172] (abudanko-mobl.ccr.corp.intel.com [10.249.225.172]) by linux.intel.com (Postfix) with ESMTP id 5E9FF5804D6; Mon, 15 Jun 2020 10:38:05 -0700 (PDT) Subject: Re: [PATCH v7 01/13] tools/libperf: introduce notion of static polled file descriptors To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Ingo Molnar , Andi Kleen , linux-kernel References: <3c92a0ad-d7d3-4e78-f0b8-1d3a7122c69e@linux.intel.com> <20200605105051.GA1404794@krava> <20200605113834.GC1404794@krava> <49eca46e-4d0e-2ae5-d7d9-e37a4d680270@linux.intel.com> <20200608084344.GA1520715@krava> <2d80a43a-54cf-3d12-92fd-066217c95d76@linux.intel.com> <20200608160758.GD1558310@krava> <345e3f6e-627d-89fc-364d-59f76071ccaa@linux.intel.com> <6a861ce4-3769-fc2a-5f9d-3003238a9736@linux.intel.com> <20200609145611.GI1558310@krava> From: Alexey Budankov Organization: Intel Corp. Message-ID: <3442cc55-d189-b349-28e4-db3367f1b23a@linux.intel.com> Date: Mon, 15 Jun 2020 20:38:04 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200609145611.GI1558310@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 On 09.06.2020 17:56, Jiri Olsa wrote: > On Mon, Jun 08, 2020 at 08:18:20PM +0300, Alexey Budankov wrote: > > SNIP > > > another idea is to forbid filter to screw the array > and return only remaining number, like below > > jirka > > > --- > diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c > index 58d44d5eee31..89f9a2193c2d 100644 > --- a/tools/lib/api/fd/array.c > +++ b/tools/lib/api/fd/array.c > @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents, > return 0; > > for (fd = 0; fd < fda->nr; ++fd) { > + if (!fda->entries[fd].events) If we change it to if (!fda->entries[fd].revents) and fix indices returned by fdarray__add() between fdarray__filter() then it is possible to check fds status by the pos and process and zero its revents prior fdarray__filter(). In this case fdarray__filter() would count the number of fds skipping the ones with zeroed revents. Looks like it solves current task avoiding explicit fds typing and even providing some more flexibility for other fds different from event and ctl ones. I will try to come up with a version implementing this approach. ~Alexey > + continue; > + > if (fda->entries[fd].revents & revents) { > if (entry_destructor) > entry_destructor(fda, fd, arg); > > + fda->entries[fd].revents = fda->entries[fd].events = 0; > continue; > } > > - if (fd != nr) { > - fda->entries[nr] = fda->entries[fd]; > - fda->priv[nr] = fda->priv[fd]; > - } > - > ++nr; > } > > - return fda->nr = nr; > + return nr; > } > > int fdarray__poll(struct fdarray *fda, int timeout) > diff --git a/tools/perf/tests/fdarray.c b/tools/perf/tests/fdarray.c > index c7c81c4a5b2b..d0c8a05aab2f 100644 > --- a/tools/perf/tests/fdarray.c > +++ b/tools/perf/tests/fdarray.c > @@ -12,6 +12,7 @@ static void fdarray__init_revents(struct fdarray *fda, short revents) > > for (fd = 0; fd < fda->nr; ++fd) { > fda->entries[fd].fd = fda->nr - fd; > + fda->entries[fd].events = revents; > fda->entries[fd].revents = revents; > } > } > @@ -29,7 +30,7 @@ static int fdarray__fprintf_prefix(struct fdarray *fda, const char *prefix, FILE > > int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_unused) > { > - int nr_fds, expected_fd[2], fd, err = TEST_FAIL; > + int nr_fds, err = TEST_FAIL; > struct fdarray *fda = fdarray__new(5, 5); > > if (fda == NULL) { > @@ -55,7 +56,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_ > > fdarray__init_revents(fda, POLLHUP); > fda->entries[2].revents = POLLIN; > - expected_fd[0] = fda->entries[2].fd; > > pr_debug("\nfiltering all but fda->entries[2]:"); > fdarray__fprintf_prefix(fda, "before", stderr); > @@ -66,17 +66,9 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_ > goto out_delete; > } > > - if (fda->entries[0].fd != expected_fd[0]) { > - pr_debug("\nfda->entries[0].fd=%d != %d\n", > - fda->entries[0].fd, expected_fd[0]); > - goto out_delete; > - } > - > fdarray__init_revents(fda, POLLHUP); > fda->entries[0].revents = POLLIN; > - expected_fd[0] = fda->entries[0].fd; > fda->entries[3].revents = POLLIN; > - expected_fd[1] = fda->entries[3].fd; > > pr_debug("\nfiltering all but (fda->entries[0], fda->entries[3]):"); > fdarray__fprintf_prefix(fda, "before", stderr); > @@ -88,14 +80,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_ > goto out_delete; > } > > - for (fd = 0; fd < 2; ++fd) { > - if (fda->entries[fd].fd != expected_fd[fd]) { > - pr_debug("\nfda->entries[%d].fd=%d != %d\n", fd, > - fda->entries[fd].fd, expected_fd[fd]); > - goto out_delete; > - } > - } > - > pr_debug("\n"); > > err = 0; >