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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6F84DC83F0C for ; Mon, 25 Aug 2025 17:46:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9EC718E005E; Mon, 25 Aug 2025 13:45:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C4B58E0038; Mon, 25 Aug 2025 13:45:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8DA678E005E; Mon, 25 Aug 2025 13:45:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 7E89B8E0038 for ; Mon, 25 Aug 2025 13:45:59 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 2C0AC118A0E for ; Mon, 25 Aug 2025 17:45:59 +0000 (UTC) X-FDA: 83816008038.11.3F78CDF Received: from mail-yw1-f179.google.com (mail-yw1-f179.google.com [209.85.128.179]) by imf24.hostedemail.com (Postfix) with ESMTP id 9FB92180005 for ; Mon, 25 Aug 2025 17:45:56 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=bytedance.com header.s=google header.b=MIQYDY7m; dmarc=pass (policy=quarantine) header.from=bytedance.com; spf=pass (imf24.hostedemail.com: domain of sunjunchao@bytedance.com designates 209.85.128.179 as permitted sender) smtp.mailfrom=sunjunchao@bytedance.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756143957; a=rsa-sha256; cv=none; b=qtJBIQCqEV4DrYDOYEZ6iuPrWVwb8ZtFH+eRrFDPjGR8ZVa6EhugwQHprJNiipWfLUTKDV vXYSl87A1SD5JR7hXx91NrQQpkeQI6dd81F2cSLKtaL/xEzQPiCBQB468JbBCIz6APV+UU e2y4d9ydbGbrp74+IwuoLziJyfJBwiw= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=bytedance.com header.s=google header.b=MIQYDY7m; dmarc=pass (policy=quarantine) header.from=bytedance.com; spf=pass (imf24.hostedemail.com: domain of sunjunchao@bytedance.com designates 209.85.128.179 as permitted sender) smtp.mailfrom=sunjunchao@bytedance.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756143957; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1OT/3jnBTfte7HdviQkf1yIS7M/qS42669Lv6VXZMcY=; b=Gk0Be+M7bFXvDsIZAF4W/mDT0inSBXeC43Qe/QPnmVyfkFatqjyJ1GVfzJTV6annZuQXBb 5PwhiK9AZ4Adld7AiDmFdZAr/s4FxIVe6rqyNJbwlVgGmUjoRpb4UGvH7Xt1PrIn4/hyLf vhkhFYDQfic1LBV1PRnvvkkqVMKTF2g= Received: by mail-yw1-f179.google.com with SMTP id 00721157ae682-71d6051aeafso39755227b3.2 for ; Mon, 25 Aug 2025 10:45:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1756143955; x=1756748755; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=1OT/3jnBTfte7HdviQkf1yIS7M/qS42669Lv6VXZMcY=; b=MIQYDY7mRjpNX4/iozKUCeSTrO85lu/o5ET1qVWzKS2uGJrdk0gwY/oBdryhhhYiN7 jgUx+UjDpmWLimx07GdCG7GXgLUg2pN2rj2bFB8KoQnrOhx9eOy5yApNA4Us3dsxpwhQ 6Ta3St42AUV3ZMAw38EYQBHxKIVTssHkmc7ktJ7L0I5kWv2JUCeIgBYA+k1lGwscSEx5 tbXh2merMlXgd4rgQf+0+StHAUiyLMgJ+qI5xx2OJKMPjgzeeHfLp9T9W3eUJm8/zuLv W4m+Ql691VlsdPoofloZjBGuZyRx0QE1yroIas35ZnuF0XrLhNGqTGBj2XzIJc37gBXJ EFog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756143955; x=1756748755; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1OT/3jnBTfte7HdviQkf1yIS7M/qS42669Lv6VXZMcY=; b=k5g+L3dDDiKlLHy8DfN2IWVw6WKdEZvz7dDZtXx/KE4ewkdG8qYgexLUASDzYB1Ss3 8dkMb/YrpTK5+AlsOFu7Tx/oRAclUdT8yUoLDA9U2t1K+mY8kRzsYIdPdYEmwgoxO1Ix QpBjOJuUZDuPPD1bxPX8h8F0jBkrTs6M0tMk4SZG91MyQa+1g9xAx8n3aUZPJlsRRrw3 nlKae2yn5BIiSIZOWXeBp5WBo2d1+rE5GgOrN0F9MmWn/gSz9PMCyHUv01jpGYksw8Iy EYLsPho/Y1fgEPpHJpOIGj/Dv4a1y0M4kwBWlGOlm5fHp5zYYAK6/GSdxocDZof7F+Kh g5eg== X-Forwarded-Encrypted: i=1; AJvYcCVN5MB6Ie9CgiBTIxm5s0ZRDbRQ0V/qgsR44WYeb/Pg325qTnSK+2ynJ4GPYD9BV8MoBuZoFesmUg==@kvack.org X-Gm-Message-State: AOJu0Yz3kZkB/fx7UO++RFQPQbUJHARRT6LMamI3INIfHXHfGDqCQzaK 2g5i59q7Jm0SCVyn3C1yTLp2ldlG6VRxtGAW5k70n/qlMXkHRKeSdEBpUiVVQybFeXBDPDcZE// l1s7PLgAIWLPVmQZiarXKH43abo8l3k2VoIb4wHZ7jA== X-Gm-Gg: ASbGnctg7kw2tG+bQ+O/v5iWM/yRuCSuqHjRLhK1iQBcuuoKbEiYsaQ8uuL9XUraDwr fcaPbSLprefKyy1ElNwOh10QWTxZ8dF1Oas8l8Hn9GcW9qobHb2zsDaEec4tBB1mfHCx2Vxv8km rV2e5bcOrDX0/gjbIjcuJKpFpqwMAHgjHSlYDu9hh9pbWOilQiDXokRCEORbAlSbu12GuIkAkRf QJ7SFFabxZT X-Google-Smtp-Source: AGHT+IEewseEoi5RyIQ11sFXi1Dz+0DgF+bccMhvM5suWzRi9juSFrm3PhDgSwCeoDygtX1TkgND9JR8BfJWU3XKEdk= X-Received: by 2002:a05:690c:3802:b0:71f:b107:4dc2 with SMTP id 00721157ae682-71fdc2dd2e4mr147859917b3.13.1756143955410; Mon, 25 Aug 2025 10:45:55 -0700 (PDT) MIME-Version: 1.0 References: <20250820111940.4105766-1-sunjunchao@bytedance.com> <20250820111940.4105766-4-sunjunchao@bytedance.com> In-Reply-To: From: Julian Sun Date: Tue, 26 Aug 2025 01:45:44 +0800 X-Gm-Features: Ac12FXz-noqncD7Sg6rActzzOUu7I8FaVkMIzxJKc6Jc3poEaZnSiD5yWERwbak Message-ID: Subject: Re: [External] Re: [PATCH] memcg: Don't wait writeback completion when release memcg. To: Tejun Heo Cc: linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, axboe@kernel.dk Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 9FB92180005 X-Stat-Signature: 1p7qyh6yfpg9cdd9xmgpehqzduueg6wj X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1756143956-608074 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi, Tejun On Sat, Aug 23, 2025 at 1:56=E2=80=AFAM Tejun Heo wrote: > > Hello, > > On Fri, Aug 22, 2025 at 04:22:09PM +0800, Julian Sun wrote: > > +struct wb_wait_queue_head { > > + wait_queue_head_t waitq; > > + wb_wait_wakeup_func_t wb_wakeup_func; > > +}; > > wait_queue_head_t itself already allows overriding the wakeup function. > Please look for init_wait_func() usages in the tree. Hopefully, that shou= ld > contain the changes within memcg. Sorry for having misunderstood what you meant before. I=E2=80=99m afraid th= at init_wait_func() cannot work the same way. Because calling init_wait_func() presupposes that we are preparing to wait for an event(like wb_wait_completion()), but waiting for such an event might lead to a hung task. Please correct me if I'm wrong. > > Thanks. > > -- > tejun Thanks, --=20 Julian Sun