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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22338C10DCE for ; Mon, 4 Dec 2023 23:59:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343536AbjLDX6z (ORCPT ); Mon, 4 Dec 2023 18:58:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234661AbjLDX6x (ORCPT ); Mon, 4 Dec 2023 18:58:53 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04EEE107 for ; Mon, 4 Dec 2023 15:58:59 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-db54a19c7d6so3751689276.3 for ; Mon, 04 Dec 2023 15:58:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701734338; x=1702339138; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=bc3wWZdTIWXynHMDoBBnLgT0pYzNdNHfaXI4uKulM+I=; b=FLAhgsNetn2k0Xo7OHCrDXsmBVkNiGRf/sj8OrCyNH87DQyF7GsvikfhBxabA6cj5P ceHWjEps0QH6FBamV8TRnY5uCO9YmDJrDJI2Ym9xmvTghiFqhhEdAIk85hwwGwo/XBjC HWQFuico5tD0R88HpPgV6WrTsUgh2noPCL44LWW2ff9uzDxS86a5pVIGpgRZOQnBOJn2 VTusOSrHttduU9Cmz8H/YwkqInN1VMB/nmUWt/ymvQ+801qEZAEFQWny2TUlGnJOZhMi Jch62C4/I62+EtF7aNMzeMOmUJd8lzBnyo6V+DiFtWPLCFNvPKWuFKVtaSvDZBhjR6ys AJbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701734338; x=1702339138; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=bc3wWZdTIWXynHMDoBBnLgT0pYzNdNHfaXI4uKulM+I=; b=GERzrsE+kgUrQhMa8o5Ocd3wBW0DggV98XhpwTVMj5akqkvp2TzvNxnkDsOWmI4DH/ 1HHXp+C/NaCN4hCUVMLfXYmauwY8GgwqeNyVNWOA7ET30IZo0uGcx7LQAlwG8smCuTkv ChqzV6flCgU0lSK0V+55HDcrRF7plYeGMBoK+2YhDCbmFVcJWBO5v+/VlzIA1uxW5/dY qmM2CBsWh7INlEz5qW5X+3AFJTvYcCbVZXQhpLJG69QMOtk+q011gfTpMq0VMa/ow1BF UTXui/Wo1VoT3beVVXDVmXkcbdiBDo974YDQDgdZNJhegCx1gp5drevjrKSaGbAivAv6 fk1w== X-Gm-Message-State: AOJu0Yz8t0ZcXq+IQkF0FYP80ELs8+2K7uTtBABYYDWa9isnoW2sFGL/ vGC4MVle1TfhVXoXTh5iOGqF+qOSU0PfFA== X-Google-Smtp-Source: AGHT+IFDrcTevAMTdK5aY6ZCZm5tMFx5J7z5a1aKvWzleHwEj72AE5vypmyjwIltbbArECOAHx0hRe9bNnWWtw== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:262e]) (user=shakeelb job=sendgmr) by 2002:a25:cf51:0:b0:db7:dce9:76d6 with SMTP id f78-20020a25cf51000000b00db7dce976d6mr189881ybg.2.1701734338283; Mon, 04 Dec 2023 15:58:58 -0800 (PST) Date: Mon, 4 Dec 2023 23:58:56 +0000 In-Reply-To: Mime-Version: 1.0 References: <20231129032154.3710765-1-yosryahmed@google.com> <20231129032154.3710765-6-yosryahmed@google.com> <20231202083129.3pmds2cddy765szr@google.com> Message-ID: <20231204235856.k4izppfsrpg2rng7@google.com> Subject: Re: [mm-unstable v4 5/5] mm: memcg: restore subtree stats flushing From: Shakeel Butt To: Yosry Ahmed Cc: Wei Xu , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Ivan Babrou , Tejun Heo , "Michal =?utf-8?Q?Koutn=C3=BD?=" , Waiman Long , kernel-team@cloudflare.com, Greg Thelen , Domenico Cerasuolo , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 04, 2023 at 03:49:01PM -0800, Yosry Ahmed wrote: [...] > > From 19af26e01f93cbf0806d75a234b78e48c1ce9d80 Mon Sep 17 00:00:00 2001 > From: Yosry Ahmed > Date: Mon, 4 Dec 2023 23:43:29 +0000 > Subject: [PATCH] mm: memcg: remove stats flushing mutex > > The mutex was intended to make the waiters sleep instead of spin, and > such that we can check the update thresholds again after acquiring the > mutex. However, the mutex has a risk of priority inversion, especially > since the underlying rstat lock can de dropped while the mutex is held. > > Synthetic testing with high concurrency of flushers shows no > regressions without the mutex, so remove it. > > Suggested-by: Shakeel Butt > Signed-off-by: Yosry Ahmed Acked-by: Shakeel Butt