From patchwork Wed Sep 13 02:20:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 13382398 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6357EE801F for ; Wed, 13 Sep 2023 02:21:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3DBE16B010F; Tue, 12 Sep 2023 22:21:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 38BDB6B0113; Tue, 12 Sep 2023 22:21:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27A536B0116; Tue, 12 Sep 2023 22:21:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 1811C6B010F for ; Tue, 12 Sep 2023 22:21:02 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id DDB2F1201CE for ; Wed, 13 Sep 2023 02:21:01 +0000 (UTC) X-FDA: 81229971522.09.5F9BB7F Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf19.hostedemail.com (Postfix) with ESMTP id 421C11A000B for ; Wed, 13 Sep 2023 02:21:00 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=MWIXfpIY; spf=pass (imf19.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1694571660; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=br6RxcKd/TjTkbpaCnmw6891aLjmucVBm8/AaQUAbqY=; b=ZBGOK619lHZxqzVY8lTUY6CGkLvvPwLhPxGD+7/eeZfqI/6ubsDpo+BJ0JM4kseqgaUmdU XFnlLEi6iLIMhda5gW/2vfsSDE4d3I9URKPjYGivqNpeIk6m9BPehCTUAnWvZjxBrfJ3Hi EuRgPzr6kr5z4ifShti1ytnAiSUJ5jA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1694571660; a=rsa-sha256; cv=none; b=JCqD4xhYxiqLAj8XbDOBww3I+hKJws2uCf3kHcTZlgdXoGoGcePpks3bRqR3rilrbwei6b eGzmKZa3gthXfGnED/KNCZJD73goqWrlF79CSDhc7wWscXDTVzfOcNPeiwbic6jlymRint qACi2eo9/1LhV6ETfsjd7+k3OVAnE9o= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=MWIXfpIY; spf=pass (imf19.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4CEDC617AF; Wed, 13 Sep 2023 02:20:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AD12C433C9; Wed, 13 Sep 2023 02:20:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694571658; bh=Ux09g9gvrxiM7e96gBaO1VxVbWHC7sVtSUZj+woij6E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MWIXfpIYm9NEP1OadcLcMILX/yRVtaPGkZh+pKnN+/VGHmrzOeD87gZ9c50xSCL8T 8eeLui/pnMGyuouBdR24HUhiq47J7olFaCqiix8Kq4z/bAX4LnLOjmPKCHsgwkMHef 4vIcYFP6dYIErFnn1lFSQTnvXscr8IxyU4/DwmPe4YKJO9t+KHzR+SqXuFkaTXctaQ C7W+xMCx27zSpzYth6tRXZLtIyQRmZqV9TEcus8xqCmCTqqdJA1Drt/Q0F1eBMDPne jqOat7YDtf5VopmWMc2o5kWXNq+AEu4tnoYc2vCsMDbgqBzP1vYASGCIzoaHADaXz3 SWxmmlSa9FS4Q== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , Steven Rostedt , damon@lists.linux.dev, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND v2 1/2] mm/damon/core: add a tracepoint for damos apply target regions Date: Wed, 13 Sep 2023 02:20:49 +0000 Message-Id: <20230913022050.2109-2-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230913022050.2109-1-sj@kernel.org> References: <20230913022050.2109-1-sj@kernel.org> MIME-Version: 1.0 X-Stat-Signature: tpbugiansi3kx4de7mtpu93wuoutyirc X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 421C11A000B X-Rspam-User: X-HE-Tag: 1694571660-779899 X-HE-Meta: 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 /lAyCQCw cHfC7vnF1DV/EJ+fsgVco2KZP1Ez7OO2/2RvuYibCCG6hWx2eE+XDb7GEjLgH1ndaPdsCbKhirLmKbv/BnaDn0R+8JnEif55scpa4pDHn+9ftL2TaCVsIYywtZDW8f6UU+Giv8VKgWB+iTx/ha41cbQBVrJdYwOKdOzbEB/0bmfhfIDXjNgVZfVGoQGQITbOwNq3+cnTY+9/QLPSHcth0Ep0KWjTzpk3Tse+yhsLG1217744/loKBBFm3beQVOLQ3fujl0StUUuOVNJLqlfMekjPaIdyh0gLDlAcGs2vPXghuwyZ98/osti/C8OAcdCG5RazN56ZGFYc1PQifnUsQcKj57g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: DAMON provides damon_aggregated tracepoint, which exposes details of each region and its access monitoring results. It is useful for getting whole monitoring results, e.g., for recording purposes. For investigations of DAMOS, DAMON Sysfs interface provides DAMOS statistics and tried_regions directory. But, those provides only statistics and snapshots. If the scheme is frequently applied and if the user needs to know every detail of DAMOS behavior, the snapshot-based interface could be insufficient and expensive. As a last resort, userspace users need to record the all monitoring results via damon_aggregated tracepoint and simulate how DAMOS would worked. It is unnecessarily complicated. DAMON kernel API users, meanwhile, can do that easily via before_damos_apply() callback field of 'struct damon_callback', though. Add a tracepoint that will be called just after before_damos_apply() callback for more convenient investigations of DAMOS. The tracepoint exposes all details about each regions, similar to damon_aggregated tracepoint. Please note that DAMOS is currently not only for memory management but also for query-like efficient monitoring results retrievals (when 'stat' action is used). Until now, only statistics or snapshots were supported. Addition of this tracepoint allows efficient full recording of DAMOS-based filtered monitoring results. Signed-off-by: SeongJae Park Reviewed-by: Steven Rostedt (Google) --- include/trace/events/damon.h | 39 ++++++++++++++++++++++++++++++++++++ mm/damon/core.c | 32 ++++++++++++++++++++++++++++- 2 files changed, 70 insertions(+), 1 deletion(-) diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h index 0b8d13bde17a..19930bb7af9a 100644 --- a/include/trace/events/damon.h +++ b/include/trace/events/damon.h @@ -9,6 +9,45 @@ #include #include +TRACE_EVENT_CONDITION(damos_before_apply, + + TP_PROTO(unsigned int context_idx, unsigned int scheme_idx, + unsigned int target_idx, struct damon_region *r, + unsigned int nr_regions, bool do_trace), + + TP_ARGS(context_idx, target_idx, scheme_idx, r, nr_regions, do_trace), + + TP_CONDITION(do_trace), + + TP_STRUCT__entry( + __field(unsigned int, context_idx) + __field(unsigned int, scheme_idx) + __field(unsigned long, target_idx) + __field(unsigned long, start) + __field(unsigned long, end) + __field(unsigned int, nr_accesses) + __field(unsigned int, age) + __field(unsigned int, nr_regions) + ), + + TP_fast_assign( + __entry->context_idx = context_idx; + __entry->scheme_idx = scheme_idx; + __entry->target_idx = target_idx; + __entry->start = r->ar.start; + __entry->end = r->ar.end; + __entry->nr_accesses = r->nr_accesses; + __entry->age = r->age; + __entry->nr_regions = nr_regions; + ), + + TP_printk("ctx_idx=%u scheme_idx=%u target_idx=%lu nr_regions=%u %lu-%lu: %u %u", + __entry->context_idx, __entry->scheme_idx, + __entry->target_idx, __entry->nr_regions, + __entry->start, __entry->end, + __entry->nr_accesses, __entry->age) +); + TRACE_EVENT(damon_aggregated, TP_PROTO(unsigned int target_id, struct damon_region *r, diff --git a/mm/damon/core.c b/mm/damon/core.c index ca631dd88b33..3ca34a252a3c 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -950,6 +950,33 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, struct timespec64 begin, end; unsigned long sz_applied = 0; int err = 0; + /* + * We plan to support multiple context per kdamond, as DAMON sysfs + * implies with 'nr_contexts' file. Nevertheless, only single context + * per kdamond is supported for now. So, we can simply use '0' context + * index here. + */ + unsigned int cidx = 0; + struct damos *siter; /* schemes iterator */ + unsigned int sidx = 0; + struct damon_target *titer; /* targets iterator */ + unsigned int tidx = 0; + bool do_trace = false; + + /* get indices for trace_damos_before_apply() */ + if (trace_damos_before_apply_enabled()) { + damon_for_each_scheme(siter, c) { + if (siter == s) + break; + sidx++; + } + damon_for_each_target(titer, c) { + if (titer == t) + break; + tidx++; + } + do_trace = true; + } if (c->ops.apply_scheme) { if (quota->esz && quota->charged_sz + sz > quota->esz) { @@ -964,8 +991,11 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, ktime_get_coarse_ts64(&begin); if (c->callback.before_damos_apply) err = c->callback.before_damos_apply(c, t, r, s); - if (!err) + if (!err) { + trace_damos_before_apply(cidx, sidx, tidx, r, + damon_nr_regions(t), do_trace); sz_applied = c->ops.apply_scheme(c, t, r, s); + } ktime_get_coarse_ts64(&end); quota->total_charged_ns += timespec64_to_ns(&end) - timespec64_to_ns(&begin); From patchwork Wed Sep 13 02:20:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 13382399 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5063DEE57CC for ; Wed, 13 Sep 2023 02:21:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D2B806B0116; Tue, 12 Sep 2023 22:21:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CDB116B0138; Tue, 12 Sep 2023 22:21:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7BB86B014B; Tue, 12 Sep 2023 22:21:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id A4D356B0116 for ; Tue, 12 Sep 2023 22:21:04 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 75C651201A5 for ; Wed, 13 Sep 2023 02:21:04 +0000 (UTC) X-FDA: 81229971648.26.60EC803 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf28.hostedemail.com (Postfix) with ESMTP id C2036C0003 for ; Wed, 13 Sep 2023 02:21:02 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=G+l4nTmJ; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf28.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1694571662; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=uOx8ScWSHBi0cBUuCTXtnmBmYJYt+uGhSfTmXKZCMoM=; b=BwifqWDAq+6g3Fzrekq2Z2shBPt0cbLL3htloUjmf9/ZvBn3FBkhckSkZw/Om5jDMy/K1s tDDubQxkO0cAoAElsNszPeEOPrCd9ZKgJsR4TGqZ33vdfdO50pX/aRIVnXWCTRMSko9Pn+ zb8eaxzGmwIoPhIX46lPyjG6PVrXoz8= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=G+l4nTmJ; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf28.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1694571662; a=rsa-sha256; cv=none; b=CGkzXhJyrZjFybW3L+SDrhouenWGhQTQ4lCBMv1Ns0mAoU5ZOGmbsoR28v9zuFTPq44slm 71sFFVt+0k/+2qSD/yXh6ki+9Ts7n9964lXBR1TCLaBWRvnoany8DrLasRUePFIhlbgXGZ 6uEwjY+UPT4i2KqY7ONLOf+XAhbEMmY= Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1549F61208; Wed, 13 Sep 2023 02:21:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2810DC433C8; Wed, 13 Sep 2023 02:21:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694571660; bh=yCdyENSSr2jBoqcU5uuhQp9Eg5ZiZzpyIfgAEWQFG08=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G+l4nTmJpLTnnS7zeMq7sUR0wx9A3+mSu7hZCG0AI8qsphhiKn/LA+9HqEahsbJkW 0VIYo5N/jkiNWdz5mJ70XL49dQ1xejMgCB+uYW73vVraKzDPiM3zegf5Y/bgvYN7IZ GFK1gmEqs8YH7k18ckYgFZfPa9qs/iuxvztNwWFzkudCTmJxoaqxbL2/lTf1DP9WWV H5iXINSUW0dB57rg3MTW4mQnxqtXQMBWidwbBIrWXua4awmxZq9qLDfCQrCqK3P3wK uKb+G+s+SL95eFpdJuOuJMiT5S4CRPUVwuI/bAZipHgcHpNPnNf8KjGOw7iRv3DTw1 rjAKkU//Pz6RA== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , Jonathan Corbet , damon@lists.linux.dev, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND v2 2/2] Docs/admin-guide/mm/damon/usage: document damos_before_apply tracepoint Date: Wed, 13 Sep 2023 02:20:50 +0000 Message-Id: <20230913022050.2109-3-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230913022050.2109-1-sj@kernel.org> References: <20230913022050.2109-1-sj@kernel.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: C2036C0003 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: 75ueg8nybo61heaz945oacjjo1b5n7ny X-HE-Tag: 1694571662-756637 X-HE-Meta: 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 5nDXKTwn eIQr0V5+rwUICHlhPKygsmR14J+mXxpc9mtjaFi3Swn4gGAzN68gFPtHTpY8YtHtdyNi5YX2gZOF3Stn8+0/NP7GXvsQICWy+dJ2w2Nksi1mVuEwgfTobeB1dLi3MUSzh5Zz2o4YzAr/hhIfTB/kzu+yDTs/QjtU3TuGpf3bSZR1fobl1MuW17syotACbWyKTEJnZc8i3pXzI8+kvXe19bz0uL2xVVLOptt4dcYmE6JxX265pXIY/PWKv0xvHL6nBvP6ek03UZFDBvTG7dxMmlEnHyoY4jgy90yKYHQRr0P6hmr6eE7cNo7JczW2pJMyrVjUHNFd8wqLIhcXjbZX5OH52YGbcbpudUH9+04CVJML31A30vt/RzBq7NQCbfFRydYj3gc+u6TcBFwrTlvPDD2duYrmHviR/c2GJ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Document damos_before_apply tracepoint on the usage document. Signed-off-by: SeongJae Park --- Documentation/admin-guide/mm/damon/usage.rst | 37 ++++++++++++++++---- 1 file changed, 30 insertions(+), 7 deletions(-) diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst index 282062b6f134..6272cd36590a 100644 --- a/Documentation/admin-guide/mm/damon/usage.rst +++ b/Documentation/admin-guide/mm/damon/usage.rst @@ -496,15 +496,24 @@ the files as above. Above is only for an example. .. _tracepoint: -Tracepoint for Monitoring Results -================================= +Tracepoints for Monitoring Results +================================== Users can get the monitoring results via the :ref:`tried_regions -` or a tracepoint, ``damon:damon_aggregated``. -While the tried regions directory is useful for getting a snapshot, the -tracepoint is useful for getting a full record of the results. While the -monitoring is turned on, you could record the tracepoint events and show -results using tracepoint supporting tools like ``perf``. For example:: +`. The interface is useful for getting a +snapshot, but it could be inefficient for fully recording all the monitoring +results. For the purpose, two trace points, namely ``damon:damon_aggregated`` +and ``damon:damos_before_apply``, are provided. ``damon:damon_aggregated`` +provides the whole monitoring results, while ``damon:damos_before_apply`` +provides the monitoring results for regions that each DAMON-based Operation +Scheme (:ref:`DAMOS `) is gonna be applied. Hence, +``damon:damos_before_apply`` is more useful for recording internal behavior of +DAMOS, or DAMOS target access +:ref:`pattern ` based query-like efficient +monitoring results recording. + +While the monitoring is turned on, you could record the tracepoint events and +show results using tracepoint supporting tools like ``perf``. For example:: # echo on > monitor_on # perf record -e damon:damon_aggregated & @@ -527,6 +536,20 @@ counter). Finally the tenth field (``X``) shows the ``age`` of the region (refer to :ref:`design ` for more details of the counter). +If the event was ``damon:damos_beofre_apply``, the ``perf script`` output would +be somewhat like below:: + + kdamond.0 47293 [000] 80801.060214: damon:damos_before_apply: ctx_idx=0 scheme_idx=0 target_idx=0 nr_regions=11 121932607488-135128711168: 0 136 + [...] + +Each line of the output represents each monitoring region that each DAMON-based +Operation Scheme was about to be applied at the traced time. The first five +fields are as usual. It shows the index of the DAMON context (``ctx_idx=X``) +of the scheme in the list of the contexts of the context's kdamond, the index +of the scheme (``scheme_idx=X``) in the list of the schemes of the context, in +addition to the output of ``damon_aggregated`` tracepoint. + + .. _debugfs_interface: debugfs Interface (DEPRECATED!)