From patchwork Mon Dec 16 16:28:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 11294753 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E01511580 for ; Mon, 16 Dec 2019 17:07:47 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B4A682082E for ; Mon, 16 Dec 2019 17:07:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Mlvwqgp4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4A682082E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:57070 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1igtqU-0002zr-6Z for patchwork-qemu-devel@patchwork.kernel.org; Mon, 16 Dec 2019 12:07:46 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57561) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1igtFn-00062c-8T for qemu-devel@nongnu.org; Mon, 16 Dec 2019 11:29:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1igtFl-0000lJ-P3 for qemu-devel@nongnu.org; Mon, 16 Dec 2019 11:29:50 -0500 Received: from mail-wr1-x444.google.com ([2a00:1450:4864:20::444]:37669) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1igtFl-0000h9-55 for qemu-devel@nongnu.org; Mon, 16 Dec 2019 11:29:49 -0500 Received: by mail-wr1-x444.google.com with SMTP id w15so8066939wru.4 for ; Mon, 16 Dec 2019 08:29:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=nb2hZFwKzalXfmKpcbYjmUeCAEo1SDTH5IqQlmfU414=; b=Mlvwqgp4qGA8Fg20kZKCRxrVTnH9nl3keRg5gX5ia4/a25JwygHQuQVfd3R0u9X/Ln jFzr/7Qpk8dRaqssdw3yIqAZe1Wd2/e8pij/SyHZN9tsh6F9r+XfXDoEObCJXf0GlzhC 68M6NEBkwvljigddmM2OrBXaigcwO3A/eYcDy2TwtQttDP+JtYqyWzjlP892pzNGHOpx dkOe9qk4bnBNuaoGgng7s0bJIdfFKXMNcFcqv1z2UI5s6KKZREO0bNf9Cwryzx5SBya7 HZFNE19pk+APZgtq3W28aKAgL0ypJ+uupV6R+OE/AgwcLI7eEpRFFiUDmWSeHo23fg59 rAdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=nb2hZFwKzalXfmKpcbYjmUeCAEo1SDTH5IqQlmfU414=; b=HoHIRVuRdGAzTkYwaczKsOt5uTpSu0Aff3i2lT9xQlGna/s/Sm2ZjSZ8eVZB9RCBp2 +d/T7LKCdoCDZZ4yujXgeZW92aBAcjvvOzgIb0ETbXxUoGMH/8BhdC1/h9ppQOB6bmgc gYzXVQ9DqRBaePe9n4VGHK3NDIbLxFaEXwtYkquM3d4Pj9fy/RNHguoF1BGoWErs9Orl g7/ajP8H9T2rvHOTaNWwmWmTOT+ImG5bYKmevHdVBX1HwlYpV+V4gKrH3BMdenfLmCPF O68g9JP4oJckskZbnSsDko8Y/BaXBAbuZQdr0c4GD9r1OrXYuP6+i+Hus5dreOuWbw3t +8BQ== X-Gm-Message-State: APjAAAUMwMIjE0tAe6+rqXAuOg6Li7yIl5DULrrq/IhhwcfJV2g/QXkY SCfRxMSH4XefLmX7MQsaOMRoc0Hs X-Google-Smtp-Source: APXvYqznP2mGIOd/oI3qbOORu/XNCRRVQ5dz+tEQGyoGG6EashnmbuSxwOjhbszs8HQ+Yial5Iaaew== X-Received: by 2002:adf:ea4f:: with SMTP id j15mr32258278wrn.356.1576513787766; Mon, 16 Dec 2019 08:29:47 -0800 (PST) Received: from 640k.lan ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id q68sm19962334wme.14.2019.12.16.08.29.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Dec 2019 08:29:47 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 60/62] qsp: Use WITH_RCU_READ_LOCK_GUARD Date: Mon, 16 Dec 2019 17:28:44 +0100 Message-Id: <1576513726-53700-61-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1576513726-53700-1-git-send-email-pbonzini@redhat.com> References: <1576513726-53700-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4864:20::444 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" The automatic rcu read lock maintenance works quite nicely in this case where it previously relied on a comment to delimit the lifetime and now has a block. Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Paolo Bonzini --- util/qsp.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/util/qsp.c b/util/qsp.c index 6226541..7d5147f 100644 --- a/util/qsp.c +++ b/util/qsp.c @@ -598,7 +598,6 @@ static void qsp_ht_delete(void *p, uint32_t h, void *htp) static void qsp_mktree(GTree *tree, bool callsite_coalesce) { - QSPSnapshot *snap; struct qht ht, coalesce_ht; struct qht *htp; @@ -610,20 +609,19 @@ static void qsp_mktree(GTree *tree, bool callsite_coalesce) * We must remain in an RCU read-side critical section until we're done * with the snapshot. */ - rcu_read_lock(); - snap = atomic_rcu_read(&qsp_snapshot); + WITH_RCU_READ_LOCK_GUARD() { + QSPSnapshot *snap = atomic_rcu_read(&qsp_snapshot); - /* Aggregate all results from the global hash table into a local one */ - qht_init(&ht, qsp_entry_no_thread_cmp, QSP_INITIAL_SIZE, - QHT_MODE_AUTO_RESIZE | QHT_MODE_RAW_MUTEXES); - qht_iter(&qsp_ht, qsp_aggregate, &ht); + /* Aggregate all results from the global hash table into a local one */ + qht_init(&ht, qsp_entry_no_thread_cmp, QSP_INITIAL_SIZE, + QHT_MODE_AUTO_RESIZE | QHT_MODE_RAW_MUTEXES); + qht_iter(&qsp_ht, qsp_aggregate, &ht); - /* compute the difference wrt the snapshot, if any */ - if (snap) { - qsp_diff(&snap->ht, &ht); + /* compute the difference wrt the snapshot, if any */ + if (snap) { + qsp_diff(&snap->ht, &ht); + } } - /* done with the snapshot; RCU can reclaim it */ - rcu_read_unlock(); htp = &ht; if (callsite_coalesce) {