From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C3BA160B96 for ; Tue, 13 Aug 2024 20:47:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723582075; cv=none; b=YBoROzT9U89rbfMeAaXR1TSLF+deKuQqbAB1yy5iPlFeHqSGsnZ1ih7Z31g7V9znddFoL0hU4mrbvjIv4r+tEd90hR/f6vTLBXB08l12vTfEI+nCDN5/gG/1BPutQPGUB4UhTuXPC1fU8bwDLPi0YyeliKaPO849C21tpXtW8Hs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723582075; c=relaxed/simple; bh=x8+0SHcDmVGIqKZHn79dfKmGygZtA2zzr59rfOJVeY0=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=PqY3D+oKfGHcamvDkZI3TNWS5vDEPdGM9iWRCfZT7YfER9sUIGglerK3ILDyrKYMZf1nDyaZqAOjegOB8i0YQz7fT4bxlQe/HPVZqv8Zd2wQga29CaVRiFWoMd8/oHghclcXCoW0dLsbRtY+A2vZJrAfSzitOYJBotrQ9rMBBCc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--kinseyho.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=j6VWNOfY; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--kinseyho.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="j6VWNOfY" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-650b621f4cdso127722447b3.1 for ; Tue, 13 Aug 2024 13:47:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1723582073; x=1724186873; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=6VTAXcSzg2nJxUF/QOoTMCzcY75N5+KjH45iaTDlnBg=; b=j6VWNOfYgpptKR0mePrlKzNq4RsmgwAa0iDL8zfyx9k0cFtydGL4fy40hsDzaw0nwm /a1XRfpHgLGWHId0TZEyoFLL1XYrdbmf6WrKdI+Rqx2PGGOq4DnQLmtGsfdaO8qAqHtb T47A1jB49KPMltSCbjr7M10KyWmovOtYg4Yrj98GFjk6MbJJAe/tMJfTnhcjnbthEjqn KmhmbV0VwS1B5wWq37uMz7sdd0gIR4PGGdeDdIotb0zlzKE6M97gVR9FQ7FvKlRkrMyX paYPHZ/ASwJDEr7shIHL1dNmqbHmCeJ8tUeHN+A+VTh9TE+Kxx7/kZ2k8JWIsVaBXly5 YB9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723582073; x=1724186873; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=6VTAXcSzg2nJxUF/QOoTMCzcY75N5+KjH45iaTDlnBg=; b=CeEvZihokkxR/LtUx0zENr/pPraqf5NJpXZCLzu9OInjK00EbbYbfmWcQV8lMBpHrB 0+3PoQBIfJvPwwZjYfVLh+xEC3pLh4tU/CTjt4VFq90QrcIsarOlzlL50vFIDElHQ/pv Ju2n2ONlfeBSBAaOFpZElsPgDtNjU5O5ZsSEJWK8kYWww7/rmSXvEMpBjfr8udT2RvyB KHMsllPj7do3rQ0Lzzb0YoEatnhwOZsqzRNuMmIsDeomom+vk27HxvKgTytlTGRhBgWq C9Vv09xPbkDhzUG00kyXyjBN4DWtiwiwEJlz3cFp5C5rlb2AyYDkCoxOITlPu7qeloAv vg8Q== X-Forwarded-Encrypted: i=1; AJvYcCUfl/HQwDkn3j40cggNCEQVcgjn1RnBN0S6R86RDqV5knhZnTXgdynoycDv+2KdCdYvpE8P05BD9shuPSYoLRKQM9shkVFGGQfoXrZs X-Gm-Message-State: AOJu0YyNj5LwTADsBWCCLpCUlfYA7uBeOqpFZV3WGqtydUIjQ2Smr6GA TQBeyLEfQsmeI5RoET5iIJZoTuDe2jsxk2R1boVLDVUqWI/XgUVQxM0k6WNWiMGxxipciXBjZYa oyVcKMSzgSA== X-Google-Smtp-Source: AGHT+IFzblsx6HVwSONVyuq1qq/U8tF5umc8wK7YjkPphN9wlYyR7AcobNhp+giR2cU9kqZsxLwEY6K/rtnFFQ== X-Received: from kinseyct.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:46b]) (user=kinseyho job=sendgmr) by 2002:a0d:d385:0:b0:673:b39a:92ea with SMTP id 00721157ae682-6ac997f8a9cmr286847b3.7.1723582072721; Tue, 13 Aug 2024 13:47:52 -0700 (PDT) Date: Tue, 13 Aug 2024 20:47:10 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.46.0.76.ge559c4bf1a-goog Message-ID: <20240813204716.842811-1-kinseyho@google.com> Subject: [PATCH mm-unstable v2 0/5] Improve mem_cgroup_iter() From: Kinsey Ho To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Yosry Ahmed , Roman Gushchin , Johannes Weiner , Michal Hocko , Shakeel Butt , Muchun Song , Tejun Heo , Zefan Li , mkoutny@suse.com, Kinsey Ho Content-Type: text/plain; charset="UTF-8" Incremental cgroup iteration is being used again [1]. This patchset improves the reliability of mem_cgroup_iter(). It also improves simplicity and code readability. [1] https://lore.kernel.org/20240514202641.2821494-1-hannes@cmpxchg.org/ -- v2: add patch to clarify css sibling linkage is RCU protected. The kernel build bot RCU sparse error from v1 has been ignored. v1: https://lore.kernel.org/20240724190214.1108049-1-kinseyho@google.com/ Kinsey Ho (5): cgroup: clarify css sibling linkage is protected by cgroup_mutex or RCU mm: don't hold css->refcnt during traversal mm: increment gen # before restarting traversal mm: restart if multiple traversals raced mm: clean up mem_cgroup_iter() include/linux/cgroup-defs.h | 6 ++- include/linux/memcontrol.h | 6 +-- kernel/cgroup/cgroup.c | 16 +++---- mm/memcontrol.c | 84 +++++++++++++++---------------------- 4 files changed, 51 insertions(+), 61 deletions(-) -- 2.46.0.76.ge559c4bf1a-goog