From nobody Mon Apr 6 01:52:20 2026 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 8877AC54EE9 for ; Tue, 13 Sep 2022 09:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231638AbiIMJMw (ORCPT ); Tue, 13 Sep 2022 05:12:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231611AbiIMJMh (ORCPT ); Tue, 13 Sep 2022 05:12:37 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60BF55A800 for ; Tue, 13 Sep 2022 02:12:36 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id q62-20020a17090a17c400b00202a3497516so8387119pja.1 for ; Tue, 13 Sep 2022 02:12:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=references:in-reply-to:message-id:date:subject:cc:to:from:from:to :cc:subject:date; bh=RludiuXI04g98bb6hCOo/Y+uQHagYxl6mhzM1wptlJE=; b=ZziSErcgXFTobtgN4y5qbgv8tURNEb5sxc0isyqeQJfLoU0RVzXarfIlNoeDn5ElEx l8gU5Xg2lvH0gIdizMMxc0mXyNlZJnn92OaJNh6aJdoe8Qf+EtKJz1nFD+Kdy96RVfSl EtJBEV9RCQrEydMLHeBhCUKUVSvkGeGfWU1cQXw0ghtjLKRiuxq00frbiw6pAKvomMBT FDg/8PJotaxvkLOYrix15q3LSA9jyJN/Ot++L4/Tx8+9GhOqtlTM/3myg+YkyOZ7+OTp 6kZwlU3F5WjuWtZYCvGk3HfP8dOw2inqKcgsVGJqnd5GoDycJbIzD8ZhsTH0mfqxULTC 2//Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=references:in-reply-to:message-id:date:subject:cc:to:from :x-gm-message-state:from:to:cc:subject:date; bh=RludiuXI04g98bb6hCOo/Y+uQHagYxl6mhzM1wptlJE=; b=3ed6c0W4nuxPQRaidEc67ruao7g9sy8Kh0inePl6VKyVooeNSanDORNv4q2lkutJ94 j5ns9sJFHJXIxkbn9lvoTrnIwY49fKqO4MOcm7rzrbSJuvdZZe8ensJqvZK0zRm4aV18 WY7TnxFh9YE/wejHZpxvvjyPze0hgDxedq+QHsn7h8jsb5QECKxbGDGzIx1w5yhnQtPN jnweNX+nqinK0/LlUg88/Mcpw8pWKfVv4e1Gixr7dKJfXRDu+lkdqoLUiUqt8ZyRXSyK iLeW4fh7CiF0uIt+fsK8/Tiv8SmzKE1CYgCj8r3yn/kOHgMNhbEVKFOy2wXsJ0fYG0xg iTsg== X-Gm-Message-State: ACgBeo3IzVpNky5VWlsQSSBCNwGje1JeV6c1HR1UYKWWxuR9VAsra+Bk FWneSwfJeX4uxH1MvxbHmw== X-Google-Smtp-Source: AA6agR5fkOMWeikIf2G4s+cnzgehLhSEMVAMumnMknm+iaDNywQoKQy3BUN6M0oQGYLVlkC5XlHvHg== X-Received: by 2002:a17:903:22c9:b0:178:18a1:d170 with SMTP id y9-20020a17090322c900b0017818a1d170mr17125135plg.2.1663060355904; Tue, 13 Sep 2022 02:12:35 -0700 (PDT) Received: from localhost.localdomain ([43.132.141.3]) by smtp.gmail.com with ESMTPSA id h10-20020a170902680a00b0015e8d4eb1d5sm7804661plk.31.2022.09.13.02.12.34 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 13 Sep 2022 02:12:35 -0700 (PDT) From: xiakaixu1987@gmail.com X-Google-Original-From: kaixuxia@tencent.com To: sj@kernel.org, akpm@linux-foundation.org Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kaixu Xia Subject: [PATCH 4/4] mm/damon/vaddr: indicate the target is invalid when 'nr_regions' is zero Date: Tue, 13 Sep 2022 17:11:27 +0800 Message-Id: <1663060287-30201-5-git-send-email-kaixuxia@tencent.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1663060287-30201-1-git-send-email-kaixuxia@tencent.com> References: <1663060287-30201-1-git-send-email-kaixuxia@tencent.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Kaixu Xia When 'init()' and 'update()' DAMON operations failed and the number of the damon_target regions is zero, the kdamond would do nothing to this monitoring target in this case. It makes no sense to run kdamond when all of monitoring targets have no regions. So add the judgement in 'target_valid()' operation to indicate the target is invalid when 'nr_regions' is zero. Signed-off-by: Kaixu Xia --- mm/damon/vaddr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index 39ea48d9cc15..65ff98d49ec0 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -598,6 +598,9 @@ static bool damon_va_target_valid(void *target) struct damon_target *t =3D target; struct task_struct *task; =20 + if (!damon_nr_regions(t)) + return false; + task =3D damon_get_task_struct(t); if (task) { put_task_struct(task); --=20 2.27.0