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=-5.3 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 5FFBFCA9EC4 for ; Tue, 29 Oct 2019 09:20:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 316CA2083E for ; Tue, 29 Oct 2019 09:20:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730515AbfJ2JUU (ORCPT ); Tue, 29 Oct 2019 05:20:20 -0400 Received: from mga12.intel.com ([192.55.52.136]:22388 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726716AbfJ2JUR (ORCPT ); Tue, 29 Oct 2019 05:20:17 -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 fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Oct 2019 02:20:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,243,1569308400"; d="scan'208";a="374490804" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.197]) ([10.237.72.197]) by orsmga005.jf.intel.com with ESMTP; 29 Oct 2019 02:20:13 -0700 Subject: Re: [PATCH RFC 2/6] perf dso: Refactor dso_cache__read() To: Jiri Olsa Cc: Peter Zijlstra , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , x86@kernel.org, Mark Rutland , Alexander Shishkin , Mathieu Poirier , Leo Yan , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org References: <20191025130000.13032-1-adrian.hunter@intel.com> <20191025130000.13032-3-adrian.hunter@intel.com> <20191028153930.GA15449@krava> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <3c5652a7-57ef-bf5e-c0aa-2332c3febff9@intel.com> Date: Tue, 29 Oct 2019 11:19:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191028153930.GA15449@krava> Content-Type: text/plain; charset=windows-1252 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 28/10/19 5:39 PM, Jiri Olsa wrote: > On Fri, Oct 25, 2019 at 03:59:56PM +0300, Adrian Hunter wrote: > > SNIP > >> +} >> >> - return ret; >> +static struct dso_cache *dso_cache__find(struct dso *dso, >> + struct machine *machine, >> + u64 offset, >> + ssize_t *ret) >> +{ >> + struct dso_cache *cache = __dso_cache__find(dso, offset); >> + >> + return cache ? cache : dso_cache__populate(dso, machine, offset, ret); >> } >> >> static ssize_t dso_cache_read(struct dso *dso, struct machine *machine, >> u64 offset, u8 *data, ssize_t size) >> { >> struct dso_cache *cache; >> + ssize_t ret = 0; >> >> - cache = dso_cache__find(dso, offset); >> - if (cache) >> - return dso_cache__memcpy(cache, offset, data, size); >> - else >> - return dso_cache__read(dso, machine, offset, data, size); >> + cache = dso_cache__find(dso, machine, offset, &ret); >> + if (!cache) >> + return ret; > > why not use the ERR_* macros to get error through the pointer > instead of adding extra argument? > OK, here's the diff for that: diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index 460330d125b6..272545624fbe 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -865,30 +866,29 @@ static ssize_t file_read(struct dso *dso, struct machine *machine, static struct dso_cache *dso_cache__populate(struct dso *dso, struct machine *machine, - u64 offset, ssize_t *ret) + u64 offset) { u64 cache_offset = offset & DSO__DATA_CACHE_MASK; struct dso_cache *cache; struct dso_cache *old; + ssize_t ret; cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE); - if (!cache) { - *ret = -ENOMEM; - return NULL; - } + if (!cache) + return ERR_PTR(-ENOMEM); if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO) - *ret = bpf_read(dso, cache_offset, cache->data); + ret = bpf_read(dso, cache_offset, cache->data); else - *ret = file_read(dso, machine, cache_offset, cache->data); + ret = file_read(dso, machine, cache_offset, cache->data); - if (*ret <= 0) { + if (ret <= 0) { free(cache); - return NULL; + return ERR_PTR(ret); } cache->offset = cache_offset; - cache->size = *ret; + cache->size = ret; old = dso_cache__insert(dso, cache); if (old) { @@ -902,23 +902,20 @@ static struct dso_cache *dso_cache__populate(struct dso *dso, static struct dso_cache *dso_cache__find(struct dso *dso, struct machine *machine, - u64 offset, - ssize_t *ret) + u64 offset) { struct dso_cache *cache = __dso_cache__find(dso, offset); - return cache ? cache : dso_cache__populate(dso, machine, offset, ret); + return cache ? cache : dso_cache__populate(dso, machine, offset); } static ssize_t dso_cache_read(struct dso *dso, struct machine *machine, u64 offset, u8 *data, ssize_t size) { - struct dso_cache *cache; - ssize_t ret = 0; + struct dso_cache *cache = dso_cache__find(dso, machine, offset); - cache = dso_cache__find(dso, machine, offset, &ret); - if (!cache) - return ret; + if (IS_ERR_OR_NULL(cache)) + return PTR_ERR(cache); return dso_cache__memcpy(cache, offset, data, size); }