Messages in this thread | | | Date | Tue, 12 Dec 2023 19:07:52 +0100 | Subject | Re: [PATCH v3 2/4] mm/ksm: add sysfs knobs for advisor | From | David Hildenbrand <> |
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On 12.12.23 19:02, Stefan Roesch wrote: > > > On Tue, Dec 12, 2023, at 5:45 AM, David Hildenbrand wrote: >> On 05.12.23 00:49, Stefan Roesch wrote: >>> 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: 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 <shr@devkernel.io> >>> --- >>> mm/ksm.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 127 insertions(+) >>> >>> diff --git a/mm/ksm.c b/mm/ksm.c >>> index b27010fa2e946..18b7185bbc65b 100644 >>> --- a/mm/ksm.c >>> +++ b/mm/ksm.c >>> @@ -3735,6 +3735,128 @@ 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 */ >>> + init_advisor(); >> >> Is the "init_advisor()" really required? >> > > The init_advisor is required for the following scenario: > - advisor is used > - advisor is turned off > - pages_to_scan is used and run for some time > - advisor is turned on again > ==> Advisor would start with two high values for the first calculation
Can't set_advisor_defaults() handle that?
-- Cheers,
David / dhildenb
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