From mboxrd@z Thu Jan 1 00:00:00 1970 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 6B473C27C47 for ; Sat, 28 Oct 2023 00:13:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346744AbjJ1ANF (ORCPT ); Fri, 27 Oct 2023 20:13:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346735AbjJ1ANB (ORCPT ); Fri, 27 Oct 2023 20:13:01 -0400 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6CB21B8 for ; Fri, 27 Oct 2023 17:12:59 -0700 (PDT) Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id 85062E5A25DF; Fri, 27 Oct 2023 17:10:02 -0700 (PDT) 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 v2 2/4] mm/ksm: add sysfs knobs for advisor Date: Fri, 27 Oct 2023 17:09:43 -0700 Message-Id: <20231028000945.2428830-3-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231028000945.2428830-1-shr@devkernel.io> References: <20231028000945.2428830-1-shr@devkernel.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds four new knobs for the KSM advisor to influence its behaviour. The knobs are: - advisor_mode: 0: no advisor (default) 1: scan time advisor - advisor_min_cpu: 15 (default, cpu usage percent) - advisor_max_cpu: 70 (default, cpu usage percent) - advisor_min_pages: 500 (default) - advisor_max_pages: 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 | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) diff --git a/mm/ksm.c b/mm/ksm.c index e18fecfb359d..042ecaeb0beb 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -351,6 +351,14 @@ static void init_advisor(void) advisor_ctx.cpu_time =3D 0; } =20 +static void set_advisor_defaults(void) +{ + if (ksm_advisor =3D=3D KSM_ADVISOR_NONE) + ksm_thread_pages_to_scan =3D DEFAULT_PAGES_TO_SCAN; + else if (ksm_advisor =3D=3D KSM_ADVISOR_SCAN_TIME) + ksm_thread_pages_to_scan =3D ksm_advisor_min_pages; +} + /* * Use previous scan time if available, otherwise use current scan time = as an * approximation for the previous scan time. @@ -3719,6 +3727,146 @@ static ssize_t smart_scan_store(struct kobject *k= obj, } KSM_ATTR(smart_scan); =20 +static ssize_t advisor_mode_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%u\n", ksm_advisor); +} + +static ssize_t advisor_mode_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, + size_t count) +{ + unsigned int mode; + int err; + + err =3D kstrtouint(buf, 10, &mode); + if (err) + return -EINVAL; + if (mode > KSM_ADVISOR_LAST) + return -EINVAL; + + /* Set advisor default values */ + ksm_advisor =3D mode; + init_advisor(); + set_advisor_defaults(); + + return count; +} +KSM_ATTR(advisor_mode); + +static ssize_t advisor_min_cpu_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%u\n", ksm_advisor_min_cpu); +} + +static ssize_t advisor_min_cpu_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err =3D kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_min_cpu =3D value; + return count; +} +KSM_ATTR(advisor_min_cpu); + +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 =3D kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_max_cpu =3D value; + return count; +} +KSM_ATTR(advisor_max_cpu); + +static ssize_t advisor_min_pages_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%lu\n", ksm_advisor_min_pages); +} + +static ssize_t advisor_min_pages_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err =3D kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_min_pages =3D value; + return count; +} +KSM_ATTR(advisor_min_pages); + +static ssize_t advisor_max_pages_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%lu\n", ksm_advisor_max_pages); +} + +static ssize_t advisor_max_pages_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long value; + + err =3D kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_max_pages =3D value; + return count; +} +KSM_ATTR(advisor_max_pages); + +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 =3D kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + if (value < 1) + return -EINVAL; + + ksm_advisor_target_scan_time =3D value; + return count; +} +KSM_ATTR(advisor_target_scan_time); + static struct attribute *ksm_attrs[] =3D { &sleep_millisecs_attr.attr, &pages_to_scan_attr.attr, @@ -3741,6 +3889,12 @@ static struct attribute *ksm_attrs[] =3D { &use_zero_pages_attr.attr, &general_profit_attr.attr, &smart_scan_attr.attr, + &advisor_mode_attr.attr, + &advisor_min_cpu_attr.attr, + &advisor_max_cpu_attr.attr, + &advisor_min_pages_attr.attr, + &advisor_max_pages_attr.attr, + &advisor_target_scan_time_attr.attr, NULL, }; =20 --=20 2.39.3