From patchwork Wed Dec 13 18:27:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 178251 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7300:3b04:b0:fb:cd0c:d3e with SMTP id c4csp7982207dys; Wed, 13 Dec 2023 10:28:09 -0800 (PST) X-Google-Smtp-Source: AGHT+IFX7nTXQYmsveloHFXXGuA6iGlwDouia7jopLQHHpiomKFooRmrEM1MuoibHa8zrKBD9OFg X-Received: by 2002:a05:6a20:938e:b0:190:9d87:f9f7 with SMTP id x14-20020a056a20938e00b001909d87f9f7mr3723047pzh.43.1702492088992; Wed, 13 Dec 2023 10:28:08 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1702492088; cv=none; d=google.com; s=arc-20160816; b=0W4BbougGrJN3l0dQLx5W+F8KJYuRg5roBGqoaNI7k3qpVHDmayY3GKtbfxBI5iqE3 NP7XarjC7McuRVBHwDpKmtD9nTWn3wLmXK5Vjazr/vllV83euKml/++GVEmzvVALW6v0 BY3HkGPzYM/jiMMY3TtL1tb/Ncocb0WgEHQ6xN6Z2doxN2nI85U6TzsdgpeA1Yd+TXN/ HXIPLNZ7rrnGiu5nDkVPN3PIW1HSEANgw9lNDZl/GCYKqHWYnYp1rKP8i3IoOGvfyFrT PG5BK+aM4IpZFFF+jydPnRmI7KmvGorQv+XciYd58rWyFl2kU4c8GsJPstaEE5xAbrAd ZqXQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=hjv8NkWfXoQ+7hZi7rLJ9o88UnzNicsuLM05tnOh3cI=; fh=sS+J4OyOC0EcVLWJpS3mBHGeO+0+dYZJ+ImCUfzsrH4=; b=HtPS7H8cn6ksJBPRQ9WSa9uTPsuLP3iKJbTH4SAmww0nlyMVbPybKbhAi8D4QV9yEn dThlzWlkvEUVTOrMV0SvMtaxW/NG0hBNXroWP+q9lymrVqR8WsiDlnD7gV2KRMcAQu78 BfQqIxfDtxy5KRVQ8fBSnDdjL5nMEGuNstuqfXD3O7jypytEdpJN8nGUPigH5y2UTG/S d2TQ7iKfns2XjYiRDDosx8SOuHSSU6ob9/U59A8VhzaDz6m45jqUzEfRf3TjQ9yNGe7L wXpaI7x6zLit6dojMigczIXHVicRBYf4/Szkd1ZIccA1aUE92Mp9sJYbo1w91mVm9Gvg 05+g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from morse.vger.email (morse.vger.email. [2620:137:e000::3:1]) by mx.google.com with ESMTPS id ks4-20020a056a004b8400b006cef66406f7si7240398pfb.276.2023.12.13.10.28.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Dec 2023 10:28:08 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id 000D7826EB7B; Wed, 13 Dec 2023 10:28:03 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442530AbjLMS1u (ORCPT + 99 others); Wed, 13 Dec 2023 13:27:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233764AbjLMS1k (ORCPT ); Wed, 13 Dec 2023 13:27:40 -0500 Received: from 66-220-144-179.mail-mxout.facebook.com (66-220-144-179.mail-mxout.facebook.com [66.220.144.179]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DBD710C for ; Wed, 13 Dec 2023 10:27:46 -0800 (PST) Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id AC6E210CFA728; Wed, 13 Dec 2023 10:27:33 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, akpm@linux-foundation.org, david@redhat.com, hannes@cmpxchg.org, riel@surriel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v4 2/4] mm/ksm: add sysfs knobs for advisor Date: Wed, 13 Dec 2023 10:27:27 -0800 Message-Id: <20231213182729.587081-3-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231213182729.587081-1-shr@devkernel.io> References: <20231213182729.587081-1-shr@devkernel.io> MIME-Version: 1.0 X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Wed, 13 Dec 2023 10:28:04 -0800 (PST) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1785192344894941385 X-GMAIL-MSGID: 1785192344894941385 This adds four new knobs for the KSM advisor to influence its behaviour. The knobs are: - advisor_mode: none: no advisor (default) scan-time: scan time advisor - advisor_max_cpu: 70 (default, cpu usage percent) - advisor_min_pages_to_scan: 500 (default) - advisor_max_pages_to_scan: 30000 (default) - advisor_target_scan_time: 200 (default in seconds) The new values will take effect on the next scan round. Signed-off-by: Stefan Roesch --- mm/ksm.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 139 insertions(+), 3 deletions(-) diff --git a/mm/ksm.c b/mm/ksm.c index 4f7b71a1f3112..f7387a6d02050 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -302,10 +302,10 @@ unsigned long ksm_zero_pages; static unsigned long ksm_pages_skipped; /* Don't scan more than max pages per batch. */ -static unsigned long ksm_advisor_max_pages = 30000; +static unsigned long ksm_advisor_max_pages_to_scan = 30000; /* At least scan this many pages per batch. */ -static unsigned long ksm_advisor_min_pages = 500; +static unsigned long ksm_advisor_min_pages_to_scan = 500; /* Min CPU for scanning pages per scan */ static unsigned int ksm_advisor_min_cpu = 10; @@ -341,6 +341,16 @@ enum ksm_advisor_type { }; static enum ksm_advisor_type ksm_advisor; +static void set_advisor_defaults(void) +{ + if (ksm_advisor == KSM_ADVISOR_NONE) { + ksm_thread_pages_to_scan = DEFAULT_PAGES_TO_SCAN; + } else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) { + advisor_ctx = (const struct advisor_ctx){ 0 }; + ksm_thread_pages_to_scan = ksm_advisor_min_pages_to_scan; + } +} + static inline void advisor_start_scan(void) { if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) @@ -434,7 +444,7 @@ static void scan_time_advisor(void) pages = min(pages, per_page_cost * ksm_advisor_max_cpu); pages = max(pages, per_page_cost * ksm_advisor_min_cpu); - pages = min(pages, ksm_advisor_max_pages); + pages = min(pages, ksm_advisor_max_pages_to_scan); /* Update advisor context */ advisor_ctx.change = change; @@ -3722,6 +3732,127 @@ static ssize_t smart_scan_store(struct kobject *kobj, } KSM_ATTR(smart_scan); +static ssize_t advisor_mode_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + const char *output; + + if (ksm_advisor == KSM_ADVISOR_NONE) + output = "[none] scan-time"; + else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) + output = "none [scan-time]"; + + return sysfs_emit(buf, "%s\n", output); +} + +static ssize_t advisor_mode_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, + size_t count) +{ + if (sysfs_streq("scan-time", buf)) + ksm_advisor = KSM_ADVISOR_SCAN_TIME; + else if (sysfs_streq("none", buf)) + ksm_advisor = KSM_ADVISOR_NONE; + else + return -EINVAL; + + /* Set advisor default values */ + set_advisor_defaults(); + + return count; +} +KSM_ATTR(advisor_mode); + +static ssize_t advisor_max_cpu_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%u\n", ksm_advisor_max_cpu); +} + +static ssize_t advisor_max_cpu_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err = kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_max_cpu = value; + return count; +} +KSM_ATTR(advisor_max_cpu); + +static ssize_t advisor_min_pages_to_scan_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%lu\n", ksm_advisor_min_pages_to_scan); +} + +static ssize_t advisor_min_pages_to_scan_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err = kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_min_pages_to_scan = value; + return count; +} +KSM_ATTR(advisor_min_pages_to_scan); + +static ssize_t advisor_max_pages_to_scan_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%lu\n", ksm_advisor_max_pages_to_scan); +} + +static ssize_t advisor_max_pages_to_scan_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err = kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_max_pages_to_scan = value; + return count; +} +KSM_ATTR(advisor_max_pages_to_scan); + +static ssize_t advisor_target_scan_time_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%lu\n", ksm_advisor_target_scan_time); +} + +static ssize_t advisor_target_scan_time_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err = kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + if (value < 1) + return -EINVAL; + + ksm_advisor_target_scan_time = value; + return count; +} +KSM_ATTR(advisor_target_scan_time); + static struct attribute *ksm_attrs[] = { &sleep_millisecs_attr.attr, &pages_to_scan_attr.attr, @@ -3744,6 +3875,11 @@ static struct attribute *ksm_attrs[] = { &use_zero_pages_attr.attr, &general_profit_attr.attr, &smart_scan_attr.attr, + &advisor_mode_attr.attr, + &advisor_max_cpu_attr.attr, + &advisor_min_pages_to_scan_attr.attr, + &advisor_max_pages_to_scan_attr.attr, + &advisor_target_scan_time_attr.attr, NULL, };