From patchwork Tue Sep 20 19:04:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 57818 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 1F0723858011 for ; Tue, 20 Sep 2022 19:04:51 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1F0723858011 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1663700691; bh=tCfgOL8qatDGUfTmgfjZMOyjtc1xASJ31+KLJnKaPds=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=o/b1NOFxiHEAbn77znhFqQQeAvq2MvtD7afqMf4umPOo2bZ5BrwqJlvWuWc9OQHnr QdEd+yIVQWrUKZMQIOfvIPP029+cuy+r3eGmsuxPwBoXWdRGHClY62Remtie5GzvqR MJsaEiADY6cbGUvJlg/7Da3ci2n/KkEd075C43Bw= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-oo1-xc33.google.com (mail-oo1-xc33.google.com [IPv6:2607:f8b0:4864:20::c33]) by sourceware.org (Postfix) with ESMTPS id E50223858C55 for ; Tue, 20 Sep 2022 19:04:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E50223858C55 Received: by mail-oo1-xc33.google.com with SMTP id h1-20020a4aa741000000b004756c611188so537842oom.4 for ; Tue, 20 Sep 2022 12:04:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:x-gm-message-state:from:to:cc:subject:date; bh=tCfgOL8qatDGUfTmgfjZMOyjtc1xASJ31+KLJnKaPds=; b=kZnLgUJDrP/R0dEgQ0xNOh4KT68rFC6f3ueY94tEybXiSeQ4pSn+EKlW2L1EuksGE5 sgkvwVGLMO/rDiohTVGko33DU/XXhTLJ/bIS2hSZk29MELf5pYWCgG0vMr89ttJzXZN8 t1UKkzif3vKmchtidBdXpEhgcyvugG1QfQG4dZVGEQ1U5iG2KcYiRWoZ+t5y5hgHiv/q lUQLlGDSAanbla+hP2AKrY+hEY0IDL6s+QpF+2daCZdeQJKXTQMayagVMtIoKFe0d1fy MDckGhKT17St+TolHn03soF6umOQznaWColv7kPFf5JNrndWrmQSjcEsW1d9kmSrmdoN B5Bw== X-Gm-Message-State: ACrzQf3gEQzZveC+Vwxcn5ikWVIqRMMS9eb+8GEWLBICi4sZKtw0o3sC zEuy6O/2yUkLtHg5c5DBbZP1aRLHCfGhB1vI X-Google-Smtp-Source: AMsMyM4wyuAKasfgF/YYKfjyHGKDuGKTUvH636vtrfw2DyFHqMCsPArEYTvWj8O2hiDNVDpUIOnCzA== X-Received: by 2002:a4a:b04e:0:b0:472:912a:63c9 with SMTP id g14-20020a4ab04e000000b00472912a63c9mr9224979oon.87.1663700658601; Tue, 20 Sep 2022 12:04:18 -0700 (PDT) Received: from mandiga.. ([2804:1b3:a7c1:c266:89ee:2da4:d02e:51c8]) by smtp.gmail.com with ESMTPSA id 43-20020a9d0bae000000b0063711d42df5sm279320oth.30.2022.09.20.12.04.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Sep 2022 12:04:17 -0700 (PDT) To: libc-alpha@sourceware.org, Wilco Dijkstra Subject: [PATCH v3] elf: Use C11 atomics on _dl_mcount Date: Tue, 20 Sep 2022 16:04:13 -0300 Message-Id: <20220920190413.3160597-1-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-12.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Adhemerval Zanella via Libc-alpha From: Adhemerval Zanella Netto Reply-To: Adhemerval Zanella Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" All atomic operation are counters, so relaxed MO should be suffice. Checked on x86_64-linux-gnu. Reviewed-by: Wilco Dijkstra --- elf/dl-profile.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/elf/dl-profile.c b/elf/dl-profile.c index ec57e3a965..c5ac9b5a3e 100644 --- a/elf/dl-profile.c +++ b/elf/dl-profile.c @@ -548,7 +548,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) size_t newfromidx; to_index = (data[narcs].self_pc / (HASHFRACTION * sizeof (*tos))); - newfromidx = catomic_exchange_and_add (&fromidx, 1) + 1; + newfromidx = atomic_fetch_add_relaxed (&fromidx, 1) + 1; froms[newfromidx].here = &data[narcs]; froms[newfromidx].link = tos[to_index]; tos[to_index] = newfromidx; @@ -558,14 +558,14 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) /* If we still have no entry stop searching and insert. */ if (*topcindex == 0) { - unsigned int newarc = catomic_exchange_and_add (narcsp, 1); + unsigned int newarc = atomic_fetch_add_relaxed (narcsp, 1) + 1; /* In rare cases it could happen that all entries in FROMS are occupied. So we cannot count this anymore. */ if (newarc >= fromlimit) goto done; - *topcindex = catomic_exchange_and_add (&fromidx, 1) + 1; + *topcindex = atomic_fetch_add_relaxed (&fromidx, 1) + 1; fromp = &froms[*topcindex]; fromp->here = &data[newarc]; @@ -573,7 +573,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) data[newarc].self_pc = selfpc; data[newarc].count = 0; fromp->link = 0; - catomic_increment (&narcs); + atomic_fetch_add_relaxed (&narcs, 1); break; } @@ -586,7 +586,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) } /* Increment the counter. */ - catomic_increment (&fromp->here->count); + atomic_fetch_add_relaxed (&fromp->here->count, 1); done: ;