From patchwork Sun Sep 10 03:40:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 13378447 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 0DAA9EEB57B for ; Sun, 10 Sep 2023 03:40:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240061AbjIJDk5 (ORCPT ); Sat, 9 Sep 2023 23:40:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229672AbjIJDk4 (ORCPT ); Sat, 9 Sep 2023 23:40:56 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25E1818F; Sat, 9 Sep 2023 20:40:52 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAF52C433C8; Sun, 10 Sep 2023 03:40:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694317251; bh=YnN+3EEg+Kt4hqil0PHaLwXJvCyERiTOIWXnLJWZVHA=; h=From:To:Cc:Subject:Date:From; b=k0R1X6O8RtpH+OZ2kVJhQU38l8/QrE6lor2MzdhBIg4zhYkXb2jXTU6ZOJCRSCsoP na2pWCtgzkU9zCgjsPasZQ3ZyWGAZV7WCasVKZpgtQJvLwYMj/aklrd4jWTJr0Myrx hCKydtcy6X4yl58GEqmTZji1keb+mVB1oNYL1fe3HJsDTZGfUY7HQf3sQeL8XanFO3 vZj6RWuo8LM/VS0rxTKJmLL/RZLNA/Hwl3p9GSpyptquRfAOhhZfkmybwoKLVZjG7K cuoHbxKUqEPhvgEPzVRHB65I8//yyFl7jzlz49BFiEhl78+BlOlEE2YIBknxwHQjFU uyW3FkLs//50w== From: SeongJae Park Cc: SeongJae Park , Andrew Morton , Jonathan Corbet , Steven Rostedt , damon@lists.linux.dev, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC 0/8] mm/damon: implement DAMOS apply intervals Date: Sun, 10 Sep 2023 03:40:40 +0000 Message-Id: <20230910034048.59191-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org DAMON-based operation schemes are applied for every aggregation interval. That is mainly because schemes are using nr_accesses, which be complete to be used for every aggregation interval. However, DAMON provides nr_accesses_bp, which is updated for each sampling interval in a way that reasonable to be used. Therefore, there is no reason to not use nr_accesses_bp instead and apply schemes for their own time interval instead of the aggregation interval. Actually, the alignment with the aggregation interval is also making some use case of DAMOS tricky. Quota setting under long aggregation interval is one such example. Suppose the aggregation interval is ten seconds, and there is a scheme having CPU quota 100ms per 1s. The scheme will actually uses 100ms per ten seconds, since it cannobe be applied before next aggregation interval. The feature is working as intended, but the results might not that intuitive for some users. This could be fixed by updating the quota to 1s per 10s. But, in the case, the CPU usage of DAMOS could look like spikes, and actually make a bad effect to other CPU-sensitive workloads. This patchset makes DAMOS schemes to use nr_accesses_bp instead of nr_accesses, and have their own timing intervals. Note that the interval is 0 by default, and it is interpreted to use the aggregation interval instead. This is for avoid making behavioral changes to the old users. Patches Seuqeunce ----------------- The first patch (patch 1/8) makes DAMOS uses nr_accesses_bp instead of nr_accesses, and following two patches (patches 2/8 and 3/8) updates DAMON sysfs interface for DAMOS tried regions and the DAMOS before_apply tracespoint to expose nr_accesses_bp instead of nr_accesses, respectively. The following two patches (patches 4/8 and 5/8) implements the scheme-specific apply interval for DAMON kernel API users and update the design document for the new feature. Finally, the following three patches (patches 6/8, 7/8, and 8/8) add support of the feature in DAMON sysfs interface and documents it on usage and ABI documents, repsectively. SeongJae Park (8): mm/damon/core: make DAMOS uses nr_accesses_bp instead of nr_accesses mm/damon/sysfs-schemes: expose nr_accesses_bp via tried_regions//nr_accesses mm/damon/core: expose nr_accesses_bp from damos_before_apply tracepoint mm/damon/core: implement scheme-specific apply interval Docs/mm/damon/design: document DAMOS apply intervals mm/damon/sysfs-schemes: support DAMOS apply interval Docs/admin-guide/mm/damon/usage: update for DAMOS apply intervals Docs/ABI/damon: update for DAMOS apply intervals .../ABI/testing/sysfs-kernel-mm-damon | 7 ++ Documentation/admin-guide/mm/damon/usage.rst | 9 ++- Documentation/mm/damon/design.rst | 3 +- include/linux/damon.h | 17 +++- include/trace/events/damon.h | 2 +- mm/damon/core.c | 80 +++++++++++++++++-- mm/damon/dbgfs.c | 3 +- mm/damon/lru_sort.c | 2 + mm/damon/reclaim.c | 2 + mm/damon/sysfs-schemes.c | 40 ++++++++-- 10 files changed, 144 insertions(+), 21 deletions(-) base-commit: 2a43f312aed581fa5044c4a0c0d20cfd4e632aa6