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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 09A65C433DF for ; Mon, 8 Jun 2020 08:09:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D137220656 for ; Mon, 8 Jun 2020 08:09:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729140AbgFHIJB (ORCPT ); Mon, 8 Jun 2020 04:09:01 -0400 Received: from mga04.intel.com ([192.55.52.120]:47531 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729075AbgFHIJA (ORCPT ); Mon, 8 Jun 2020 04:09:00 -0400 IronPort-SDR: zuJh6/P6g1dlplYp+TMWRh2jpoBULq0NYyray/JlzMO/WtTMGf1IoPfKXimfJDu5/vCt9C7iBr 9zt3G1UgaSFA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2020 01:08:59 -0700 IronPort-SDR: 3AVKcQ2unnKJNV1nHrHB3Xphz+4a+T7KyV4GZt1jCXlpRnyCJcSkAKoZhTNZ2RQXYMW/BL+NKA y5vvE2ra+uRg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,487,1583222400"; d="scan'208";a="472611541" Received: from linux.intel.com ([10.54.29.200]) by fmsmga005.fm.intel.com with ESMTP; 08 Jun 2020 01:08:59 -0700 Received: from [10.249.230.149] (abudanko-mobl.ccr.corp.intel.com [10.249.230.149]) by linux.intel.com (Postfix) with ESMTP id 0A78E5805B5; Mon, 8 Jun 2020 01:08:56 -0700 (PDT) Subject: Re: [PATCH v7 01/13] tools/libperf: introduce notion of static polled file descriptors From: Alexey Budankov To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Ingo Molnar , Andi Kleen , linux-kernel References: <5de4b954-24f0-1e8d-5a0d-7b12783b8218@linux.intel.com> <3c92a0ad-d7d3-4e78-f0b8-1d3a7122c69e@linux.intel.com> <20200605105051.GA1404794@krava> <20200605113834.GC1404794@krava> Organization: Intel Corp. Message-ID: <49eca46e-4d0e-2ae5-d7d9-e37a4d680270@linux.intel.com> Date: Mon, 8 Jun 2020 11:08:56 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: 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 05.06.2020 19:15, Alexey Budankov wrote: > > On 05.06.2020 14:38, Jiri Olsa wrote: >> On Fri, Jun 05, 2020 at 12:50:54PM +0200, Jiri Olsa wrote: >>> On Wed, Jun 03, 2020 at 06:52:59PM +0300, Alexey Budankov wrote: >>>> >>>> Implement adding of file descriptors by fdarray__add_stat() to >>>> fix-sized (currently 1) stat_entries array located at struct fdarray. >>>> Append added file descriptors to the array used by poll() syscall >>>> during fdarray__poll() call. Copy poll() result of the added >>>> descriptors from the array back to the storage for analysis. >>>> >>>> Signed-off-by: Alexey Budankov >>>> --- >>>> tools/lib/api/fd/array.c | 42 +++++++++++++++++++++++- >>>> tools/lib/api/fd/array.h | 7 ++++ >>>> tools/lib/perf/evlist.c | 11 +++++++ >>>> tools/lib/perf/include/internal/evlist.h | 2 ++ >>>> 4 files changed, 61 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c >>>> index 58d44d5eee31..b0027f2169c7 100644 >>>> --- a/tools/lib/api/fd/array.c >>>> +++ b/tools/lib/api/fd/array.c >>>> @@ -11,10 +11,16 @@ >>>> >>>> void fdarray__init(struct fdarray *fda, int nr_autogrow) >>>> { >>>> + int i; >>>> + >>>> fda->entries = NULL; >>>> fda->priv = NULL; >>>> fda->nr = fda->nr_alloc = 0; >>>> fda->nr_autogrow = nr_autogrow; >>>> + >>>> + fda->nr_stat = 0; >>>> + for (i = 0; i < FDARRAY__STAT_ENTRIES_MAX; i++) >>>> + fda->stat_entries[i].fd = -1; >>>> } >>>> >>>> int fdarray__grow(struct fdarray *fda, int nr) >>>> @@ -83,6 +89,20 @@ int fdarray__add(struct fdarray *fda, int fd, short revents) >>>> return pos; >>>> } >>>> >>>> +int fdarray__add_stat(struct fdarray *fda, int fd, short revents) >>>> +{ >>>> + int pos = fda->nr_stat; >>>> + >>>> + if (pos >= FDARRAY__STAT_ENTRIES_MAX) >>>> + return -1; >>>> + >>>> + fda->stat_entries[pos].fd = fd; >>>> + fda->stat_entries[pos].events = revents; >>>> + fda->nr_stat++; >>>> + >>>> + return pos; >>>> +} >>>> + >>>> int fdarray__filter(struct fdarray *fda, short revents, >>>> void (*entry_destructor)(struct fdarray *fda, int fd, void *arg), >>>> void *arg) >>>> @@ -113,7 +133,27 @@ int fdarray__filter(struct fdarray *fda, short revents, >>>> >>>> int fdarray__poll(struct fdarray *fda, int timeout) >>>> { >>>> - return poll(fda->entries, fda->nr, timeout); >>>> + int nr, i, pos, res; >>>> + >>>> + nr = fda->nr; >>>> + >>>> + for (i = 0; i < fda->nr_stat; i++) { >>>> + if (fda->stat_entries[i].fd != -1) { >>>> + pos = fdarray__add(fda, fda->stat_entries[i].fd, >>>> + fda->stat_entries[i].events); >>> >>> so every call to fdarray__poll will add whatever is >>> in stat_entries to entries? how is it removed? >>> >>> I think you should either follow what Adrian said >>> and put 'static' descriptors early and check for >>> filter number to match it as an 'quick fix' >>> >>> or we should fix it for real and make it generic >>> >>> so currently the interface is like this: >>> >>> pos1 = fdarray__add(a, fd1 ... ); >>> pos2 = fdarray__add(a, fd2 ... ); >>> pos3 = fdarray__add(a, fd2 ... ); >>> >>> fdarray__poll(a); >>> >>> num = fdarray__filter(a, revents, destructor, arg); >>> >>> when fdarray__filter removes some of the fds the 'pos1,pos2,pos3' >>> indexes are not relevant anymore > > and that is why the return value of fdarray__add() should be converted > to bool (added/not added). Currently the return value is used as bool > only allover the calling code. > > fdarray__add_fixed() brings the notion of fd with fixed pos which is > valid after fdarray__add_fixed() call so the pos could be used to access > pos fd poll status after poll() call. > > pos = fdarray__add_fixed(array, fd); > fdarray_poll(array); > revents = fdarray_fixed_revents(array, pos); > fdarray__del(array, pos); So how is it about just adding _revents() and _del() for fixed fds with correction of retval to bool for fdarray__add()? ~Alexey