From patchwork Fri Nov 5 20:47:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12605877 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 132A1C433FE for ; Fri, 5 Nov 2021 20:47:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B922261059 for ; Fri, 5 Nov 2021 20:47:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B922261059 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 5B2BB9400E8; Fri, 5 Nov 2021 16:47:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 562BB9400C1; Fri, 5 Nov 2021 16:47:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 451A99400E8; Fri, 5 Nov 2021 16:47:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0222.hostedemail.com [216.40.44.222]) by kanga.kvack.org (Postfix) with ESMTP id 31FD39400C1 for ; Fri, 5 Nov 2021 16:47:19 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id EEF9B77994 for ; Fri, 5 Nov 2021 20:47:18 +0000 (UTC) X-FDA: 78776061756.23.7413121 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf23.hostedemail.com (Postfix) with ESMTP id D5CD49000386 for ; Fri, 5 Nov 2021 20:47:05 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 4CBE860240; Fri, 5 Nov 2021 20:47:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1636145237; bh=0/VO9mZme1WGl9HFW/lP6xGAQOzN6ikx7PmGkXLrNoQ=; h=Date:From:To:Subject:In-Reply-To:From; b=IIrfZGBMDil1oT+8zAAB97rQYu8fCnmum5UPNqil6ZW4wvwH2kUBIHCVFbKfGsPvk qLfYAHdIs+h24gmlj5CiM5xT0IoRZRujnG3c8niJ5PydHR6MqfT/zRs5iWaEJIgTKW 4PnLrUmIO10axJ3w/mU17UmN30TU3P6tEc3FGUNI= Date: Fri, 05 Nov 2021 13:47:16 -0700 From: Andrew Morton To: akpm@linux-foundation.org, amit@kernel.org, benh@kernel.crashing.org, corbet@lwn.net, david@redhat.com, dwmw@amazon.com, elver@google.com, foersleo@amazon.de, gthelen@google.com, Jonathan.Cameron@huawei.com, linux-mm@kvack.org, markubo@amazon.de, mm-commits@vger.kernel.org, rientjes@google.com, shakeelb@google.com, shuah@kernel.org, sj@kernel.org, torvalds@linux-foundation.org Subject: [patch 240/262] mm/damon/schemes: implement size quota for schemes application speed control Message-ID: <20211105204716.KEDy5p9T4%akpm@linux-foundation.org> In-Reply-To: <20211105133408.cccbb98b71a77d5e8430aba1@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=IIrfZGBM; dmarc=none; spf=pass (imf23.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D5CD49000386 X-Stat-Signature: ap4dpezsd3ihb7o8ze1n9aizb6a9brz1 X-HE-Tag: 1636145225-672357 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: From: SeongJae Park Subject: mm/damon/schemes: implement size quota for schemes application speed control There could be arbitrarily large memory regions fulfilling the target data access pattern of a DAMON-based operation scheme. In the case, applying the action of the scheme could incur too high overhead. To provide an intuitive way for avoiding it, this commit implements a feature called size quota. If the quota is set, DAMON tries to apply the action only up to the given amount of memory regions within a given time window. Link: https://lkml.kernel.org/r/20211019150731.16699-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: Amit Shah Cc: Benjamin Herrenschmidt Cc: David Hildenbrand Cc: David Rientjes Cc: David Woodhouse Cc: Greg Thelen Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: Leonard Foerster Cc: Marco Elver Cc: Markus Boehme Cc: Shakeel Butt Cc: Shuah Khan Signed-off-by: Andrew Morton --- include/linux/damon.h | 36 +++++++++++++++++++++--- mm/damon/core.c | 60 ++++++++++++++++++++++++++++++++++------ mm/damon/dbgfs.c | 4 ++ 3 files changed, 87 insertions(+), 13 deletions(-) --- a/include/linux/damon.h~mm-damon-schemes-implement-size-quota-for-schemes-application-speed-control +++ a/include/linux/damon.h @@ -90,6 +90,26 @@ enum damos_action { }; /** + * struct damos_quota - Controls the aggressiveness of the given scheme. + * @sz: Maximum bytes of memory that the action can be applied. + * @reset_interval: Charge reset interval in milliseconds. + * + * To avoid consuming too much CPU time or IO resources for applying the + * &struct damos->action to large memory, DAMON allows users to set a size + * quota. The quota can be set by writing non-zero values to &sz. If the size + * quota is set, DAMON tries to apply the action only up to &sz bytes within + * &reset_interval. + */ +struct damos_quota { + unsigned long sz; + unsigned long reset_interval; + +/* private: For charging the quota */ + unsigned long charged_sz; + unsigned long charged_from; +}; + +/** * struct damos - Represents a Data Access Monitoring-based Operation Scheme. * @min_sz_region: Minimum size of target regions. * @max_sz_region: Maximum size of target regions. @@ -98,13 +118,20 @@ enum damos_action { * @min_age_region: Minimum age of target regions. * @max_age_region: Maximum age of target regions. * @action: &damo_action to be applied to the target regions. + * @quota: Control the aggressiveness of this scheme. * @stat_count: Total number of regions that this scheme is applied. * @stat_sz: Total size of regions that this scheme is applied. * @list: List head for siblings. * - * For each aggregation interval, DAMON applies @action to monitoring target - * regions fit in the condition and updates the statistics. Note that both - * the minimums and the maximums are inclusive. + * For each aggregation interval, DAMON finds regions which fit in the + * condition (&min_sz_region, &max_sz_region, &min_nr_accesses, + * &max_nr_accesses, &min_age_region, &max_age_region) and applies &action to + * those. To avoid consuming too much CPU time or IO resources for the + * &action, "a is used. + * + * After applying the &action to each region, &stat_count and &stat_sz is + * updated to reflect the number of regions and total size of regions that the + * &action is applied. */ struct damos { unsigned long min_sz_region; @@ -114,6 +141,7 @@ struct damos { unsigned int min_age_region; unsigned int max_age_region; enum damos_action action; + struct damos_quota quota; unsigned long stat_count; unsigned long stat_sz; struct list_head list; @@ -310,7 +338,7 @@ struct damos *damon_new_scheme( unsigned long min_sz_region, unsigned long max_sz_region, unsigned int min_nr_accesses, unsigned int max_nr_accesses, unsigned int min_age_region, unsigned int max_age_region, - enum damos_action action); + enum damos_action action, struct damos_quota *quota); void damon_add_scheme(struct damon_ctx *ctx, struct damos *s); void damon_destroy_scheme(struct damos *s); --- a/mm/damon/core.c~mm-damon-schemes-implement-size-quota-for-schemes-application-speed-control +++ a/mm/damon/core.c @@ -89,7 +89,7 @@ struct damos *damon_new_scheme( unsigned long min_sz_region, unsigned long max_sz_region, unsigned int min_nr_accesses, unsigned int max_nr_accesses, unsigned int min_age_region, unsigned int max_age_region, - enum damos_action action) + enum damos_action action, struct damos_quota *quota) { struct damos *scheme; @@ -107,6 +107,11 @@ struct damos *damon_new_scheme( scheme->stat_sz = 0; INIT_LIST_HEAD(&scheme->list); + scheme->quota.sz = quota->sz; + scheme->quota.reset_interval = quota->reset_interval; + scheme->quota.charged_sz = 0; + scheme->quota.charged_from = 0; + return scheme; } @@ -530,15 +535,25 @@ static void kdamond_reset_aggregated(str } } +static void damon_split_region_at(struct damon_ctx *ctx, + struct damon_target *t, struct damon_region *r, + unsigned long sz_r); + static void damon_do_apply_schemes(struct damon_ctx *c, struct damon_target *t, struct damon_region *r) { struct damos *s; - unsigned long sz; damon_for_each_scheme(s, c) { - sz = r->ar.end - r->ar.start; + struct damos_quota *quota = &s->quota; + unsigned long sz = r->ar.end - r->ar.start; + + /* Check the quota */ + if (quota->sz && quota->charged_sz >= quota->sz) + continue; + + /* Check the target regions condition */ if (sz < s->min_sz_region || s->max_sz_region < sz) continue; if (r->nr_accesses < s->min_nr_accesses || @@ -546,22 +561,51 @@ static void damon_do_apply_schemes(struc continue; if (r->age < s->min_age_region || s->max_age_region < r->age) continue; - s->stat_count++; - s->stat_sz += sz; - if (c->primitive.apply_scheme) + + /* Apply the scheme */ + if (c->primitive.apply_scheme) { + if (quota->sz && quota->charged_sz + sz > quota->sz) { + sz = ALIGN_DOWN(quota->sz - quota->charged_sz, + DAMON_MIN_REGION); + if (!sz) + goto update_stat; + damon_split_region_at(c, t, r, sz); + } c->primitive.apply_scheme(c, t, r, s); + quota->charged_sz += sz; + } if (s->action != DAMOS_STAT) r->age = 0; + +update_stat: + s->stat_count++; + s->stat_sz += sz; } } static void kdamond_apply_schemes(struct damon_ctx *c) { struct damon_target *t; - struct damon_region *r; + struct damon_region *r, *next_r; + struct damos *s; + + damon_for_each_scheme(s, c) { + struct damos_quota *quota = &s->quota; + + if (!quota->sz) + continue; + + /* New charge window starts */ + if (time_after_eq(jiffies, quota->charged_from + + msecs_to_jiffies( + quota->reset_interval))) { + quota->charged_from = jiffies; + quota->charged_sz = 0; + } + } damon_for_each_target(t, c) { - damon_for_each_region(r, t) + damon_for_each_region_safe(r, next_r, t) damon_do_apply_schemes(c, t, r); } } --- a/mm/damon/dbgfs.c~mm-damon-schemes-implement-size-quota-for-schemes-application-speed-control +++ a/mm/damon/dbgfs.c @@ -188,6 +188,8 @@ static struct damos **str_to_schemes(con *nr_schemes = 0; while (pos < len && *nr_schemes < max_nr_schemes) { + struct damos_quota quota = {}; + ret = sscanf(&str[pos], "%lu %lu %u %u %u %u %u%n", &min_sz, &max_sz, &min_nr_a, &max_nr_a, &min_age, &max_age, &action, &parsed); @@ -200,7 +202,7 @@ static struct damos **str_to_schemes(con pos += parsed; scheme = damon_new_scheme(min_sz, max_sz, min_nr_a, max_nr_a, - min_age, max_age, action); + min_age, max_age, action, "a); if (!scheme) goto fail;