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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFE32C76196 for ; Tue, 28 Mar 2023 06:17:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232628AbjC1GRf (ORCPT ); Tue, 28 Mar 2023 02:17:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232502AbjC1GRF (ORCPT ); Tue, 28 Mar 2023 02:17:05 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0CC835B6 for ; Mon, 27 Mar 2023 23:16:49 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id q15-20020a63d60f000000b00502e1c551aaso3002136pgg.21 for ; Mon, 27 Mar 2023 23:16:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1679984209; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=+vNiceMoZ2PdzrNG/xVeRzEo7O+ovCZNHcQMp7VClk4=; b=FtVms547YGVdf9XAqjguoo0WST2Bomcq4pMeCW3qlg0ksZV5swPoVz0GmrxFu8vfrh HBzgJptVGGKy7geKpBPvC2PsWo0HmjT2F27i9dbdVA6zCF4EYemeZRNrh89DbSPqLObX h82tbSvZ/WCeLjLtii1Meb+k3BLVneGl+TdsHqmfTXT/vAFZIC+/S3Aw9k3ElSrpUy7X 9xgxQRUTlE19S9rQfATi59HRnf65TEpEpviTmJbLID2U9/qvSayVfcGFQGEl03zvUEu5 uDhGnK3XWBy1kJngfOB04Odcd1UeEO5WA33WjKyVDhleLQy8k50zMQSY0RXklX82o1Jn CmFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679984209; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+vNiceMoZ2PdzrNG/xVeRzEo7O+ovCZNHcQMp7VClk4=; b=kK8uZbg+oTUmTeBmvVzUVdy6zltfhI3DEFToy5S6M/JHn5FIpxHBwFt1upFEvHfsIT jshcRb5WjddkuxwlmFt8nKatoq1GqrBgxzeQm7k9seG+Il1wjvNL9OPNrHiy1ecmOu37 eNgK8XHO+cDCHwyY7K8sK4ST6eo5JsKGviOe7ygz3oPAdiO7xSimxXjH/O7iAt9Ldcaq 7VCtGNrSMjGsTsooUcN2OC96pDb6VSjWOBNNvAcCxdLS5JURdcLTE4vooYkLhYLBNdSL UpFGvu7JRQhNv2KcQcvnV5DZSeeqCJvwrKsj0sBzEpNKXdb0tUbhK9g26Vrgg5npWZsq Tkiw== X-Gm-Message-State: AAQBX9e8SZ8OHEX4bVAYpG/M7glCdUkbh0YI/c9MfUYyQs5L+AWkvQeQ lZp11N31zOqDrCMdqfZKnoirl8GzxYYQ/JaP X-Google-Smtp-Source: AKy350az2ZQxKTBjGyFUiNza+YDGvWpTHjavWcHAugAuQk4rmOEm1wQoqfQkURL2u01jT9Cm3t+xr5muiADnxiOT X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a05:6a00:1a46:b0:625:c7de:48c1 with SMTP id h6-20020a056a001a4600b00625c7de48c1mr7269994pfv.4.1679984209151; Mon, 27 Mar 2023 23:16:49 -0700 (PDT) Date: Tue, 28 Mar 2023 06:16:33 +0000 In-Reply-To: <20230328061638.203420-1-yosryahmed@google.com> Mime-Version: 1.0 References: <20230328061638.203420-1-yosryahmed@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230328061638.203420-5-yosryahmed@google.com> Subject: [PATCH v1 4/9] cgroup: rstat: add WARN_ON_ONCE() if flushing outside task context From: Yosry Ahmed To: Tejun Heo , Josef Bacik , Jens Axboe , Zefan Li , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , "=?UTF-8?q?Michal=20Koutn=C3=BD?=" Cc: Vasily Averin , cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, Yosry Ahmed Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org rstat flushing is too expensive to perform in irq context. The previous patch removed the only context that may invoke an rstat flush from irq context, add a WARN_ON_ONCE() to detect future violations, or those that we are not aware of. Signed-off-by: Yosry Ahmed --- kernel/cgroup/rstat.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index d3252b0416b6..c2571939139f 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -176,6 +176,8 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep) { int cpu; + /* rstat flushing is too expensive for irq context */ + WARN_ON_ONCE(!in_task()); lockdep_assert_held(&cgroup_rstat_lock); for_each_possible_cpu(cpu) { -- 2.40.0.348.gf938b09366-goog