From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4FE1928387 for ; Wed, 13 Dec 2023 18:51:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="G5/0gELS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF6DAC433CA; Wed, 13 Dec 2023 18:51:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1702493514; bh=SbS6KVOMc+qJ241qYkBI4jWVb/+WNibqH/wbfHR2KgM=; h=Date:To:From:Subject:From; b=G5/0gELSTHG6/G5EeQWvxy3V1J/MXXB/G4E59n8z8QzOy6CqWEPRhm+Z9k8TASQLg bF6b4f8c7HqnwRU8xXQ9yrb/yc1m9oxOsiOtbuseK/pQ7nunl8Rojgg8aSXLYG3KU5 7JFMC64G0gw/NgGsPsaLsD/FwE1REX1FnwRBPDUQ= Date: Wed, 13 Dec 2023 10:51:54 -0800 To: mm-commits@vger.kernel.org,riel@surriel.com,hannes@cmpxchg.org,david@redhat.com,shr@devkernel.io,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-ksm-add-sysfs-knobs-for-advisor.patch added to mm-unstable branch Message-Id: <20231213185154.AF6DAC433CA@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/ksm: add sysfs knobs for advisor has been added to the -mm mm-unstable branch. Its filename is mm-ksm-add-sysfs-knobs-for-advisor.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ksm-add-sysfs-knobs-for-advisor.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Stefan Roesch Subject: mm/ksm: add sysfs knobs for advisor Date: Wed, 13 Dec 2023 10:27:27 -0800 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. Link: https://lkml.kernel.org/r/20231213182729.587081-3-shr@devkernel.io Signed-off-by: Stefan Roesch Cc: David Hildenbrand Cc: Johannes Weiner Cc: Rik van Riel Signed-off-by: Andrew Morton --- mm/ksm.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 139 insertions(+), 3 deletions(-) --- a/mm/ksm.c~mm-ksm-add-sysfs-knobs-for-advisor +++ a/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; @@ -3724,6 +3734,127 @@ static ssize_t smart_scan_store(struct k } 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, @@ -3746,6 +3877,11 @@ 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, }; _ Patches currently in -mm which might be from shr@devkernel.io are mm-ksm-add-ksm-advisor.patch mm-ksm-add-sysfs-knobs-for-advisor.patch mm-ksm-add-tracepoint-for-ksm-advisor.patch mm-ksm-document-ksm-advisor-and-its-sysfs-knobs.patch