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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no 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 06609C10DCE for ; Fri, 13 Mar 2020 20:17:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE41F20637 for ; Fri, 13 Mar 2020 20:17:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Und9Fuua" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726892AbgCMURD (ORCPT ); Fri, 13 Mar 2020 16:17:03 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:44857 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726480AbgCMURD (ORCPT ); Fri, 13 Mar 2020 16:17:03 -0400 Received: by mail-wr1-f66.google.com with SMTP id l18so13649344wru.11; Fri, 13 Mar 2020 13:17:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to; bh=XOtjPzu8hP+iCuLMAjq0wZ2LsERKW6jgS14BUr9BC8A=; b=Und9FuuajHuhLitN++eMQwK9QvTmb8P68OQUjXzVFgaATpxXoVIguc3k8ZUUS7A+Rw vjuTm+yKdCQ8+JsYpyxy8sOxFG9O/ZQglUje3B0CLRtKdnYtqse0mkFWf8I4CiJGniqS fB8MisM+KjCABsVnA9sktAJXWI6duofnltkPjSACH3ckau9lbJlZjd44k00ZGwsRE+8V /YQVH+IDpfkPdWk4d1bQIqpmMV9gognIutW2ggAWd5HzY8kv2BqwVqOoefaRviMda3+C pa6Dag34BJHcSBw6a3I2Thtd0NY75X9CilqU0PlcdOvSuTgz9g6DfTAYJezgcUc8aNNO K4XQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to; bh=XOtjPzu8hP+iCuLMAjq0wZ2LsERKW6jgS14BUr9BC8A=; b=ZavcY/ynVGi5l5Vlp1bE+f+HyClg5uNP6RcX4xg8ZaaIhhGhzL7UpbGctRKrx6+1QK 3m9ioJ3Ikj5GpI+/t85hqprGDXBxLxH3MwiUV/bADyGe2dLVgwUfRV4sHd70BKSoDMRP X/5x16Dl5P5AiyGsKOWUqVuNmR26OboRh1M/IMeV/c28Oms6o5h83/G4akfHI8EjZVIP qVbDslLRkvAy/j2fVocMy2RZdn8KcBi1ZuDXDzBSU1z60UYzlXSuOEdIinjPkV9CPez9 a55s2RobF7S09PCxDxR8F2oXt9mVPN6rA1Z3LIXs+v51TABcUHzT3g9+R40ha6RP+SLG b7CQ== X-Gm-Message-State: ANhLgQ3PmSftZoEkO0cM8AE57dZmdND1HIcTI4Kvj2AR1DbFMLxUXATp htKU6vtQoKcBpyeufctuPyk= X-Google-Smtp-Source: ADFU+vtmqobzopOGR/xCwGyyqwYOTZ5kNJKM1jUat5dAtqgdVPODPmKRnf6k/UkpsN7dTOXOSBOS9g== X-Received: by 2002:adf:b652:: with SMTP id i18mr3318672wre.310.1584130621241; Fri, 13 Mar 2020 13:17:01 -0700 (PDT) Received: from localhost.localdomain ([2a02:2450:10d2:194d:6183:2c38:fb6d:576a]) by smtp.gmail.com with ESMTPSA id d7sm7634380wrc.25.2020.03.13.13.16.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Mar 2020 13:17:00 -0700 (PDT) From: SeongJae Park To: Jonathan Cameron Cc: SeongJae Park , akpm@linux-foundation.org, SeongJae Park , aarcange@redhat.com, yang.shi@linux.alibaba.com, acme@kernel.org, alexander.shishkin@linux.intel.com, amit@kernel.org, brendan.d.gregg@gmail.com, brendanhiggins@google.com, cai@lca.pw, colin.king@canonical.com, corbet@lwn.net, dwmw@amazon.com, jolsa@redhat.com, kirill@shutemov.name, mark.rutland@arm.com, mgorman@suse.de, minchan@kernel.org, mingo@redhat.com, namhyung@kernel.org, peterz@infradead.org, rdunlap@infradead.org, rientjes@google.com, rostedt@goodmis.org, shuah@kernel.org, sj38.park@gmail.com, vbabka@suse.cz, vdavydov.dev@gmail.com, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Re: [PATCH v6 02/14] mm/damon: Implement region based sampling Date: Fri, 13 Mar 2020 21:16:49 +0100 Message-Id: <20200313201649.26646-1-sj38.park@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200313172954.00001f3c@Huawei.com> (raw) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, 13 Mar 2020 17:29:54 +0000 Jonathan Cameron wrote: > On Mon, 24 Feb 2020 13:30:35 +0100 > SeongJae Park wrote: > > > From: SeongJae Park > > > > This commit implements DAMON's basic access check and region based > > sampling mechanisms. This change would seems make no sense, mainly > > because it is only a part of the DAMON's logics. Following two commits > > will make more sense. > > [...] > > Came across a minor issue inline. kthread_run calls kthread_create. > That gives a potential sleep while atomic issue given the spin lock. > > Can probably be fixed by preallocating the thread then starting it later. > > Jonathan [...] > > +/* > > + * Start or stop the kdamond > > + * > > + * Returns 0 if success, negative error code otherwise. > > + */ > > +static int damon_turn_kdamond(struct damon_ctx *ctx, bool on) > > +{ > > + spin_lock(&ctx->kdamond_lock); > > + ctx->kdamond_stop = !on; > > + if (!ctx->kdamond && on) { > > + ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond"); > > Can't do this under a spin lock. Good catch! And, agree to your suggestion. I will fix this in that way! Thanks, SeongJae Park