| Message ID | 20231204234906.1237478-3-shr@devkernel.io (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/ksm: Add ksm advisor | expand |
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? > + set_advisor_defaults(); That function should go to this patch.
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 >> + set_advisor_defaults(); > > That function should go to this patch. > > > I'll move it to this patch. I'll also look if I can should move init_advisor() to this patch. > -- > Cheers, > > David / dhildenb
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?
On Tue, Dec 12, 2023, at 10:07 AM, David Hildenbrand wrote: > 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? > Yes, I can move the advisor_ctx = (const struct advisor_ctx){ 0 }; into set_advisor_defaults(). > -- > Cheers, > > David / dhildenb
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(); + 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_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 = kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_min_pages = 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 = kstrtoul(buf, 10, &value); + if (err) + return -EINVAL; + + ksm_advisor_max_pages = 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 = 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, @@ -3757,6 +3879,11 @@ 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_attr.attr, + &advisor_max_pages_attr.attr, + &advisor_target_scan_time_attr.attr, NULL, };
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(+)