From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f73.google.com (mail-ed1-f73.google.com [209.85.208.73]) (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 09E4D1DA4E for ; Mon, 27 Jan 2025 21:46:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738014397; cv=none; b=n5K3yFdh57BPN0HpJcvQVpiyGGmyIcRxmIpW4SR670OxjN/O3d23Skq91eV2veNrCkt2jDJPs/nEg7B0BwGQWHRIT+KKrBKOhEGOQRbtlhkWlmNcktxmHDLKf1sfUrwjSYuZnYloNXZr7/vCGKFoPO4qUxn2hd7oaLQ7sDlfktw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738014397; c=relaxed/simple; bh=UNdn4HPIfvvj9VZ3uxXlevNSLhKbroFgXDSJgEATaVs=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=UYFuagtYi8JpV9Wppjpd13Ll4wCfmCtCUkJ+aIJsjsoG73xG9JjCmMyx/e3eEfTdCfN3wbwo4YbTTkfP2OcVDNTLpdfmWNoOk9sYklHD7NIyPfytTxZIkOtopTGu3kZHr8eH+GpXMJDZOjYQebx8S7ikr+vndRqaJ9yIQA0qY1g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mclapinski.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=oc0GJYQt; arc=none smtp.client-ip=209.85.208.73 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--mclapinski.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="oc0GJYQt" Received: by mail-ed1-f73.google.com with SMTP id 4fb4d7f45d1cf-5d3f3d6a999so4598167a12.0 for ; Mon, 27 Jan 2025 13:46:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738014394; x=1738619194; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=sy1JlawxVbQmxkhNYCv/CozJXbpDFTEaCjWdXQXq84E=; b=oc0GJYQtxJr/r8Y1Sr5Yen19jPNeEXjQJHlUVAFdbsU3oO4OecZveZU9Rv9U4EcsyO aenAEo/rYiLqEo8xZMh3AgXqAL0nDKOPC5L69kOIx7/K7QY1pGNxJSqq+JfDUypDKFb3 Z10Y96wWmbNPpqKtrHYQAw5UXEZhz/CNP5LRrmZexJoZAWr7L3h4Zn0YWHPboVi1K9eW AXW2m1464+fQciRmY0WQeDW94OTAHuaJF3jLj7tsZ1XNFpuLySuJuqt3zucAV/pKvA1R RsP8TRtjbujRdc/tjyDM1975lJcpz5FOp6AkQcF3/da8XQ9YbJQeTD/WZCN1ea0+PlIg d5HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738014394; x=1738619194; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=sy1JlawxVbQmxkhNYCv/CozJXbpDFTEaCjWdXQXq84E=; b=cyWKDR/ZBIvcJnsuu+bgZx3iSjtAH/cgIVUh691AuJlMszHK6MW3XirJ64WNA5630J nh1tfBynmFO92Pm8tuhb7K5IDjxze+WZA+ZFM/rH5EzeABfznFY+CIfSL4jZxy7zRebm R56TPRQqBoOaaTG/fcgwbIpuvL6DD2Pa8WHwzycvjf4By6zaDB6kSOCuzEp28xdUw8XF aj+ri3f5Y2oT5rtjNwTHDlBeEHBZstZ3pjfi/le7ZnzRiKETEczWgDmguQKiF6YGHDWb BDfJYsUT5afvzv3KdxZ5/APleZJbUMVpFjbt4M2wyRNPMQIT3AZkcqBha2pzIgPy1yYT Lhrw== X-Forwarded-Encrypted: i=1; AJvYcCWnperv+JD1v+xk4KeoAoewBSfzgbXieyB+ORa9Hx4mS7eijilkhNju5f0fnrNzi7T2fKeR+FGjSb576rk=@vger.kernel.org X-Gm-Message-State: AOJu0Yw2eY9TIli/79N2VB+fdkD+G9B3XvvIWGhsgZFo4RNMsfMNVc/4 99lKDm2Uy13EDhNz0YJetln1oBzLERE3MDYiqVuoVY/JOal6hNLanwsD7Cux5lbQNtqzrGwvRNS 4KrPqfWIey0B7GqlifA== X-Google-Smtp-Source: AGHT+IGwM2B3nNZTOo1ItMReN6P5kqCT7ubnYCju8SAgZqsZuRxmAdKLeOGBzhYvzGmtPAgGsMNobRgy04+z+fqv X-Received: from edbev12.prod.google.com ([2002:a05:6402:540c:b0:5cf:c034:73b2]) (user=mclapinski job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:4413:b0:5d0:ea2a:726c with SMTP id 4fb4d7f45d1cf-5db7d2facf5mr33809378a12.8.1738014394456; Mon, 27 Jan 2025 13:46:34 -0800 (PST) Date: Mon, 27 Jan 2025 22:46:25 +0100 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 2.48.1.262.g85cc9f2d1e-goog Message-ID: <20250127214627.4021412-1-mclapinski@google.com> Subject: [PATCH v2 0/2] mm/compaction: allow more aggressive proactive compaction From: Michal Clapinski To: Andrew Morton , Vlastimil Babka , Pasha Tatashin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Clapinski Content-Type: text/plain; charset="UTF-8" Our goal is to keep memory usage of a VM low on the host. For that reason, we use free page reporting which by default reports free pages of order 9 and larger to the host to be freed. The feature works well only if the memory in the guest is not fragmented below pages of order 9. Proactive compaction can be reused to achieve defragmentation after some parameter tweaking. When the fragmentation score (lower is better) gets larger than the high watermark, proactive compaction kicks in. Compaction stops when the score goes below the low watermark (or no progress is made and backoff kicks in). Let's define the difference between high and low watermarks as leeway. Before these changes, the minimum possible value for low watermark was 5 and the leeway was hardcoded to 10 (so minimum possible value for high watermark was 15). v2: Change commit msgs and document the new sysctl. Michal Clapinski (2): mm/compaction: remove low watermark cap for proactive compaction mm/compaction: make proactive compaction high watermark configurable via sysctl Documentation/admin-guide/sysctl/vm.rst | 17 +++++++++++++++++ mm/compaction.c | 14 ++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-) -- 2.48.1.262.g85cc9f2d1e-goog