From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 940D784A2F for ; Tue, 27 Aug 2024 23:11:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724800300; cv=none; b=Ii958PnCZv4fpRwIpdQEwKInhwsUQ98+7RJOt6rKkpDwUs/Kk5OHt41nn9nd1kQICqPGwbqPdwT2scRgi9CUJ2RHz05D+0x7yEpwh6fT0m4QhXhmBdLGymiUjBboXkHxPHBkAu/nmQtyWCOTvlUAKTl+rT12IAAAKno3Djzhywg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724800300; c=relaxed/simple; bh=b819xJzDCg1+dk7jllpcdrwtTiyQMm4H+rcQN4p0pz0=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=fe1JENFx7oMsDQjniwZejbU+Ne6NdN+imcnlP/uyNYzVKyadNRTtVTIs9+6dol7WuTiDNDrErSKZ0/3UrBIMuKrNqzZ3u/bZRCX8FMn64dbEV4OdcTU191brLCy/1YGNdnLxM3BURe0tS2E408RKIn+tPY8+lS9AC+cbgiUainw= 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=0TBbrvcL; arc=none smtp.client-ip=209.85.128.202 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="0TBbrvcL" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6c3982a0c65so115910747b3.1 for ; Tue, 27 Aug 2024 16:11:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1724800297; x=1725405097; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=JRXP1C0L9voxT40sWvjxPogEtoEBvjhm/X4/q2n2W9c=; b=0TBbrvcLgOjCAtLQv8Qz4Ofg/uAgZXrl38JqWxA40eoX4ZbwnPC1D1grE9fnjgVKzP rMu2s2nqkPGWihNJKSZ0WS2cDXhBedJfOCrc0XsALCvRVbsMh2Xcsaxub96HApa6RBrC BMWj3OdUBmIaAGX1Jb4XzTIDihQq5GFtlmMX1IJ2AuftOJCQSQqXZ8CtxTW4nVzOohGF ltbf9hqhCwKtoTYG/c1HbkR42AhTB11qRz4d7buhfxyQiVdZHPaeZq6lPSvWf7hF/iwP O8lzZ0lz8FYkoyUnKjK5Ix9AotM2620Pg1OmarspWaxn3WGfVTM/OqrQtS4PkdmF1oLY 9vAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724800297; x=1725405097; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=JRXP1C0L9voxT40sWvjxPogEtoEBvjhm/X4/q2n2W9c=; b=uyiRpmji0+xUnonGY4WPRzq2q+PnuO9p3wwEgu7qW+TYI8kgA8xyL2PqUMDaLtFQ1r upGmh3iP4ZlZ4vci/TqCA3dFWbJy+nNXfHUXX18Chpsjhgd3lPx+/HhvzLrAyHtPQeh8 tY3/OqIE5aH/An57qc+CTEUq9ixXXesnHMY1QSpMWlq9kx0H/TsrGS6b9fcjyhzF4flU f5GKxM2Ba40H8cTtwrG1ayzoT3wGvFdEpNOI6CPcqR3Q65UQLBZ0A4xqBVRLfuM4nL70 fz+ABmby1rkVxfQ/T5+pCzQ0a9bba+6N+Cr4A1GgEG1FcHIuUie/aNtZvdx/rIOjpeNj cHEQ== X-Forwarded-Encrypted: i=1; AJvYcCV9NFctlzblJvSqwYWEtethzHlwKSuY+YUuDHXJrCcyYBPt47/neaUx6lc4ZmCcMPkW8qrN1tR20ulNiIU=@vger.kernel.org X-Gm-Message-State: AOJu0YziI2cSr8Hc6/hwVAIrMyZaNIg0BQFT8JDVLi0c/BULYX193gjG /1Q5ANnRFT8oLYjhXxGXMO2CkcOfLPoM7lQYuSuU4xWHS0bspvIGdqFmggTAYB45dG3a1Gl5R3T XGlh+fzdd9A== X-Google-Smtp-Source: AGHT+IGP8ZXcqFy3ObKj9gE3VPxOyLGlu672j0UH7tOda9KMrjA/lA/qb29hd5HzRIX/vZ1Z+4FIf+zXIg37dw== X-Received: from kinseyct.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:46b]) (user=kinseyho job=sendgmr) by 2002:a05:690c:6008:b0:62c:f6fd:5401 with SMTP id 00721157ae682-6d171a7c46dmr807b3.6.1724800297538; Tue, 27 Aug 2024 16:11:37 -0700 (PDT) Date: Tue, 27 Aug 2024 23:07:37 +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 2.46.0.295.g3b9ea8a38a-goog Message-ID: <20240827230753.2073580-1-kinseyho@google.com> Subject: [PATCH mm-unstable v3 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/ --- v3: Removed __rcu tag from patch 2/5 which removes the need for rcu_dereference(). This helps readability. v2: https://lore.kernel.org/20240813204716.842811-1-kinseyho@google.com/ 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 | 4 +- kernel/cgroup/cgroup.c | 16 +++---- mm/memcontrol.c | 84 +++++++++++++++---------------------- 4 files changed, 50 insertions(+), 60 deletions(-) -- 2.46.0.295.g3b9ea8a38a-goog