From patchwork Mon Feb 28 08:13:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 12762537 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 24D01C41535 for ; Mon, 28 Feb 2022 08:13:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1D65B8D0008; Mon, 28 Feb 2022 03:13:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C8AA8D0007; Mon, 28 Feb 2022 03:13:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E30608D0003; Mon, 28 Feb 2022 03:13:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id B35F98D0006 for ; Mon, 28 Feb 2022 03:13:27 -0500 (EST) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id 8D49881065 for ; Mon, 28 Feb 2022 08:13:27 +0000 (UTC) X-FDA: 79191474054.11.8B6B6BE Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf04.hostedemail.com (Postfix) with ESMTP id E8A6A40004 for ; Mon, 28 Feb 2022 08:13:26 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4554B60FC5; Mon, 28 Feb 2022 08:13:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34D6EC340F7; Mon, 28 Feb 2022 08:13:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646036006; bh=KddJdFqVOnq0xfhpG7XfrROWOOfyL2vi8LybdSNAuAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eOaS0cZTCGEKizv7WXc4cbDiBQNt/wL730I+FiDxE26p9x5SYan3c73iR7TOl5PHz ttfKeUedOAWzERNVGxfPZE5Z2x3XS2kJVINkSGQI2EO+UevZBCCuJCh95Ttdm5MML/ 8UnyEvIUmknKVBiPzhuZLjNzti4RDy3Kh8lVFbD7S8zcqJy7Dte/NBS3SMdzAH6PoC 3ubaJf47ELIRRnjm2hYM9U6Q6qTnWyjQ/drxxWhLee+PKQTbd+klQ9j+mCm3A9KnkJ 15tgbVeyQfX4HIlt3orIRSP7xbdK7x5ZvXY3pZwbA0hsXgpitkuFxDX5mnvdeMB+S7 q5BUYjb26/dYQ== From: SeongJae Park To: akpm@linux-foundation.org Cc: corbet@lwn.net, skhan@linuxfoundation.org, rientjes@google.com, xhao@linux.alibaba.com, gregkh@linuxfoundation.org, linux-damon@amazon.com, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, SeongJae Park Subject: [PATCH v3 04/13] mm/damon/sysfs: Link DAMON for virtual address spaces monitoring Date: Mon, 28 Feb 2022 08:13:05 +0000 Message-Id: <20220228081314.5770-5-sj@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220228081314.5770-1-sj@kernel.org> References: <20220228081314.5770-1-sj@kernel.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: E8A6A40004 X-Stat-Signature: b5awm1rq7ox3nnawjaxgfjsfj7gqmufg Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=eOaS0cZT; spf=pass (imf04.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 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1646036006-167081 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: This commit links the DAMON sysfs interface to DAMON so that users can control DAMON via the interface. In detail, this commit makes writing 'on' to 'state' file constructs DAMON contexts based on values that users have written to relevant sysfs files and start the context. It supports only virtual address spaces monitoring at the moment, though. The files hierarchy of DAMON sysfs interface after this commit is shown below. In the below figure, parents-children relations are represented with indentations, each directory is having ``/`` suffix, and files in each directory are separated by comma (","). /sys/kernel/mm/damon/admin │ kdamonds/nr_kdamonds │ │ 0/state,pid │ │ │ contexts/nr_contexts │ │ │ │ 0/operations │ │ │ │ │ monitoring_attrs/ │ │ │ │ │ │ intervals/sample_us,aggr_us,update_us │ │ │ │ │ │ nr_regions/min,max │ │ │ │ │ targets/nr_targets │ │ │ │ │ │ 0/pid_target │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... The usage is straightforward. Writing a number ('N') to each 'nr_*' file makes directories named '0' to 'N-1'. Users can construct DAMON contexts by writing proper values to the files in the straightforward manner and start each kdamond by writing 'on' to 'kdamonds//state'. Signed-off-by: SeongJae Park --- mm/damon/sysfs.c | 192 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 189 insertions(+), 3 deletions(-) diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 87cf28ae6a6f..9221c93db6cc 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -806,22 +806,208 @@ static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond) kobject_put(&kdamond->contexts->kobj); } +static bool damon_sysfs_ctx_running(struct damon_ctx *ctx) +{ + bool running; + + mutex_lock(&ctx->kdamond_lock); + running = ctx->kdamond != NULL; + mutex_unlock(&ctx->kdamond_lock); + return running; +} + static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return -EINVAL; + struct damon_sysfs_kdamond *kdamond = container_of(kobj, + struct damon_sysfs_kdamond, kobj); + struct damon_ctx *ctx = kdamond->damon_ctx; + bool running; + + if (!ctx) + running = false; + else + running = damon_sysfs_ctx_running(ctx); + + return sysfs_emit(buf, "%s\n", running ? "on" : "off"); +} + +static int damon_sysfs_set_attrs(struct damon_ctx *ctx, + struct damon_sysfs_attrs *sys_attrs) +{ + struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals; + struct damon_sysfs_ul_range *sys_nr_regions = + sys_attrs->nr_regions_range; + + return damon_set_attrs(ctx, sys_intervals->sample_us, + sys_intervals->aggr_us, sys_intervals->update_us, + sys_nr_regions->min, sys_nr_regions->max); +} + +static void damon_sysfs_destroy_targets(struct damon_ctx *ctx) +{ + struct damon_target *t, *next; + + damon_for_each_target_safe(t, next, ctx) { + if (ctx->ops.id == DAMON_OPS_VADDR) + put_pid(t->pid); + damon_destroy_target(t); + } +} + +static int damon_sysfs_set_targets(struct damon_ctx *ctx, + struct damon_sysfs_targets *sysfs_targets) +{ + int i; + + for (i = 0; i < sysfs_targets->nr; i++) { + struct damon_sysfs_target *sys_target = + sysfs_targets->targets_arr[i]; + struct damon_target *t = damon_new_target(); + + if (!t) { + damon_sysfs_destroy_targets(ctx); + return -ENOMEM; + } + if (ctx->ops.id == DAMON_OPS_VADDR) { + t->pid = find_get_pid(sys_target->pid); + if (!t->pid) { + damon_sysfs_destroy_targets(ctx); + return -EINVAL; + } + } + damon_add_target(ctx, t); + } + return 0; +} + +static void damon_sysfs_before_terminate(struct damon_ctx *ctx) +{ + struct damon_target *t, *next; + + if (ctx->ops.id != DAMON_OPS_VADDR) + return; + + mutex_lock(&ctx->kdamond_lock); + damon_for_each_target_safe(t, next, ctx) { + put_pid(t->pid); + damon_destroy_target(t); + } + mutex_unlock(&ctx->kdamond_lock); +} + +static struct damon_ctx *damon_sysfs_build_ctx( + struct damon_sysfs_context *sys_ctx) +{ + struct damon_ctx *ctx = damon_new_ctx(); + int err; + + if (!ctx) + return ERR_PTR(-ENOMEM); + + err = damon_select_ops(ctx, sys_ctx->ops_id); + if (err) + goto out; + err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs); + if (err) + goto out; + err = damon_sysfs_set_targets(ctx, sys_ctx->targets); + if (err) + goto out; + + ctx->callback.before_terminate = damon_sysfs_before_terminate; + return ctx; + +out: + damon_destroy_ctx(ctx); + return ERR_PTR(err); +} + +static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond) +{ + struct damon_ctx *ctx; + int err; + + if (kdamond->damon_ctx && + damon_sysfs_ctx_running(kdamond->damon_ctx)) + return -EBUSY; + /* TODO: support multiple contexts per kdamond */ + if (kdamond->contexts->nr != 1) + return -EINVAL; + + if (kdamond->damon_ctx) + damon_destroy_ctx(kdamond->damon_ctx); + kdamond->damon_ctx = NULL; + + ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + err = damon_start(&ctx, 1, false); + if (err) { + damon_destroy_ctx(ctx); + return err; + } + kdamond->damon_ctx = ctx; + return err; +} + +static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond) +{ + if (!kdamond->damon_ctx) + return -EINVAL; + return damon_stop(&kdamond->damon_ctx, 1); + /* + * To allow users show final monitoring results of already turned-off + * DAMON, we free kdamond->damon_ctx in next + * damon_sysfs_turn_damon_on(), or kdamonds_nr_store() + */ } static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { - return -EINVAL; + struct damon_sysfs_kdamond *kdamond = container_of(kobj, + struct damon_sysfs_kdamond, kobj); + ssize_t ret; + + if (!mutex_trylock(&damon_sysfs_lock)) + return -EBUSY; + if (sysfs_streq(buf, "on")) + ret = damon_sysfs_turn_damon_on(kdamond); + else if (sysfs_streq(buf, "off")) + ret = damon_sysfs_turn_damon_off(kdamond); + else + ret = -EINVAL; + mutex_unlock(&damon_sysfs_lock); + if (!ret) + ret = count; + return ret; } static ssize_t pid_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return -EINVAL; + struct damon_sysfs_kdamond *kdamond = container_of(kobj, + struct damon_sysfs_kdamond, kobj); + struct damon_ctx *ctx; + int pid; + + if (!mutex_trylock(&damon_sysfs_lock)) + return -EBUSY; + ctx = kdamond->damon_ctx; + if (!ctx) { + pid = -1; + goto out; + } + mutex_lock(&ctx->kdamond_lock); + if (!ctx->kdamond) + pid = -1; + else + pid = ctx->kdamond->pid; + mutex_unlock(&ctx->kdamond_lock); +out: + mutex_unlock(&damon_sysfs_lock); + return sysfs_emit(buf, "%d\n", pid); } static void damon_sysfs_kdamond_release(struct kobject *kobj)