| Message ID | 20210527125707.3760259-1-liushixin2@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/page_alloc: fix counting of managed_pages | expand |
+ Baoquan On 2021/5/27 20:57, Liu Shixin wrote: > The commit f63661566fad (mm/page_alloc.c: clear out zone->lowmem_reserve[] > if the zone is empty) clear out zone->lowmem_reserve[] if zone is empty. > But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to zero, > zone_managed_pages(zone) is not counted in the managed_pages either. This is > inconsistent with the description of lowmen_reserve, so fix it. > > Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") > Reported-by: yangerkun <yangerkun@huawei.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > mm/page_alloc.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index aaa1655cf682..49a2efce5a84 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8061,14 +8061,14 @@ static void setup_per_zone_lowmem_reserve(void) > unsigned long managed_pages = 0; > > for (j = i + 1; j < MAX_NR_ZONES; j++) { > - if (clear) { > - zone->lowmem_reserve[j] = 0; > - } else { > - struct zone *upper_zone = &pgdat->node_zones[j]; > + struct zone *upper_zone = &pgdat->node_zones[j]; > + > + managed_pages += zone_managed_pages(upper_zone); > > - managed_pages += zone_managed_pages(upper_zone); > + if (clear) > + zone->lowmem_reserve[j] = 0; > + else > zone->lowmem_reserve[j] = managed_pages / ratio; > - } > } > } > }
On 05/27/21 at 08:57pm, Liu Shixin wrote: > The commit f63661566fad (mm/page_alloc.c: clear out zone->lowmem_reserve[] > if the zone is empty) clear out zone->lowmem_reserve[] if zone is empty. > But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to zero, > zone_managed_pages(zone) is not counted in the managed_pages either. This is > inconsistent with the description of lowmen_reserve, so fix it. Right, this is a good catch. Thanks for the fixing. Is it worth adding words in Documentation/admin-guide/sysctl/vm.rst to notice this? Reviewed-by: Baoquan He <bhe@redhat.com> Thanks Baoquan > > Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") > Reported-by: yangerkun <yangerkun@huawei.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > mm/page_alloc.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index aaa1655cf682..49a2efce5a84 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8061,14 +8061,14 @@ static void setup_per_zone_lowmem_reserve(void) > unsigned long managed_pages = 0; > > for (j = i + 1; j < MAX_NR_ZONES; j++) { > - if (clear) { > - zone->lowmem_reserve[j] = 0; > - } else { > - struct zone *upper_zone = &pgdat->node_zones[j]; > + struct zone *upper_zone = &pgdat->node_zones[j]; > + > + managed_pages += zone_managed_pages(upper_zone); > > - managed_pages += zone_managed_pages(upper_zone); > + if (clear) > + zone->lowmem_reserve[j] = 0; > + else > zone->lowmem_reserve[j] = managed_pages / ratio; > - } > } > } > } > -- > 2.18.0.huawei.25 > >
On 2021/5/28 7:47, Baoquan He wrote: > On 05/27/21 at 08:57pm, Liu Shixin wrote: >> The commit f63661566fad (mm/page_alloc.c: clear out zone->lowmem_reserve[] >> if the zone is empty) clear out zone->lowmem_reserve[] if zone is empty. >> But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to zero, >> zone_managed_pages(zone) is not counted in the managed_pages either. This is >> inconsistent with the description of lowmen_reserve, so fix it. > Right, this is a good catch. Thanks for the fixing. > > Is it worth adding words in Documentation/admin-guide/sysctl/vm.rst > to notice this? > > Reviewed-by: Baoquan He <bhe@redhat.com> > > Thanks > Baoquan With this patch, It's consistent with the calculation description of zone[i]'s protection[j]. This is implicit in the description so I don't think it's necessary to notice this. >> Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") >> Reported-by: yangerkun <yangerkun@huawei.com> >> Signed-off-by: Liu Shixin <liushixin2@huawei.com> >> --- >> mm/page_alloc.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index aaa1655cf682..49a2efce5a84 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -8061,14 +8061,14 @@ static void setup_per_zone_lowmem_reserve(void) >> unsigned long managed_pages = 0; >> >> for (j = i + 1; j < MAX_NR_ZONES; j++) { >> - if (clear) { >> - zone->lowmem_reserve[j] = 0; >> - } else { >> - struct zone *upper_zone = &pgdat->node_zones[j]; >> + struct zone *upper_zone = &pgdat->node_zones[j]; >> + >> + managed_pages += zone_managed_pages(upper_zone); >> >> - managed_pages += zone_managed_pages(upper_zone); >> + if (clear) >> + zone->lowmem_reserve[j] = 0; >> + else >> zone->lowmem_reserve[j] = managed_pages / ratio; >> - } >> } >> } >> } >> -- >> 2.18.0.huawei.25 >> >> > . >
On 27.05.21 14:57, Liu Shixin wrote: > The commit f63661566fad (mm/page_alloc.c: clear out zone->lowmem_reserve[] > if the zone is empty) clear out zone->lowmem_reserve[] if zone is empty. > But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to zero, > zone_managed_pages(zone) is not counted in the managed_pages either. This is > inconsistent with the description of lowmen_reserve, so fix it. > > Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") > Reported-by: yangerkun <yangerkun@huawei.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > mm/page_alloc.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index aaa1655cf682..49a2efce5a84 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8061,14 +8061,14 @@ static void setup_per_zone_lowmem_reserve(void) > unsigned long managed_pages = 0; > > for (j = i + 1; j < MAX_NR_ZONES; j++) { > - if (clear) { > - zone->lowmem_reserve[j] = 0; > - } else { > - struct zone *upper_zone = &pgdat->node_zones[j]; > + struct zone *upper_zone = &pgdat->node_zones[j]; > + > + managed_pages += zone_managed_pages(upper_zone); > > - managed_pages += zone_managed_pages(upper_zone); > + if (clear) > + zone->lowmem_reserve[j] = 0; > + else > zone->lowmem_reserve[j] = managed_pages / ratio; > - } > } > } > } > Acked-by: David Hildenbrand <david@redhat.com>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index aaa1655cf682..49a2efce5a84 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8061,14 +8061,14 @@ static void setup_per_zone_lowmem_reserve(void) unsigned long managed_pages = 0; for (j = i + 1; j < MAX_NR_ZONES; j++) { - if (clear) { - zone->lowmem_reserve[j] = 0; - } else { - struct zone *upper_zone = &pgdat->node_zones[j]; + struct zone *upper_zone = &pgdat->node_zones[j]; + + managed_pages += zone_managed_pages(upper_zone); - managed_pages += zone_managed_pages(upper_zone); + if (clear) + zone->lowmem_reserve[j] = 0; + else zone->lowmem_reserve[j] = managed_pages / ratio; - } } } }
The commit f63661566fad (mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty) clear out zone->lowmem_reserve[] if zone is empty. But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to zero, zone_managed_pages(zone) is not counted in the managed_pages either. This is inconsistent with the description of lowmen_reserve, so fix it. Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") Reported-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> --- mm/page_alloc.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)