* Re: [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space
2023-08-29 2:41 [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space Liu Shixin
@ 2023-08-29 2:12 ` Huang, Ying
2023-08-29 15:23 ` Yosry Ahmed
1 sibling, 0 replies; 4+ messages in thread
From: Huang, Ying @ 2023-08-29 2:12 UTC (permalink / raw)
To: Liu Shixin
Cc: Yosry Ahmed, Michal Hocko, Johannes Weiner, Roman Gushchin,
Shakeel Butt, Muchun Song, Andrew Morton, wangkefeng.wang,
linux-kernel, cgroups, linux-mm
Liu Shixin <liushixin2@huawei.com> writes:
> When spaces of swap devices are exhausted, only file pages can be reclaimed.
> But there are still some swapcache pages in anon lru list. This can lead
> to a premature out-of-memory.
>
> The problem is found with such step:
>
> Firstly, set a 9MB disk swap space, then create a cgroup with 10MB
> memory limit, then runs an program to allocates about 15MB memory.
>
> The problem occurs occasionally, which may need about 100 times.
>
> Fix it by checking number of swapcache pages in can_reclaim_anon_pages().
> If the number is not zero, return true either. Moreover, add a new bit
> swapcache_only in struct scan_control to skip isolating anon pages that
> are not swapcache when only swapcache pages can be reclaimed to accelerate
> reclaim efficiency.
>
> Link: https://lore.kernel.org/linux-mm/14e15f31-f3d3-4169-8ed9-fb36e57cf578@huawei.com/
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>
> Tested-by: Yosry Ahmed <yosryahmed@google.com>
LGTM, Thanks!
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
> ---
> include/linux/swap.h | 6 ++++++
> mm/memcontrol.c | 8 ++++++++
> mm/vmscan.c | 29 +++++++++++++++++++++++++++--
> 3 files changed, 41 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 456546443f1f..0318e918bfa4 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -669,6 +669,7 @@ static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_p
> }
>
> extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
> +extern long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg);
> extern bool mem_cgroup_swap_full(struct folio *folio);
> #else
> static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
> @@ -691,6 +692,11 @@ static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
> return get_nr_swap_pages();
> }
>
> +static inline long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
> +{
> + return total_swapcache_pages();
> +}
> +
> static inline bool mem_cgroup_swap_full(struct folio *folio)
> {
> return vm_swap_full();
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index e8ca4bdcb03c..c465829db92b 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -7567,6 +7567,14 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
> return nr_swap_pages;
> }
>
> +long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
> +{
> + if (mem_cgroup_disabled())
> + return total_swapcache_pages();
> +
> + return memcg_page_state(memcg, NR_SWAPCACHE);
> +}
> +
> bool mem_cgroup_swap_full(struct folio *folio)
> {
> struct mem_cgroup *memcg;
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 1080209a568b..e73e2df8828d 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -137,6 +137,9 @@ struct scan_control {
> /* Always discard instead of demoting to lower tier memory */
> unsigned int no_demotion:1;
>
> + /* Swap space is exhausted, only reclaim swapcache for anon LRU */
> + unsigned int swapcache_only:1;
> +
> /* Allocation order */
> s8 order;
>
> @@ -613,10 +616,20 @@ static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg,
> */
> if (get_nr_swap_pages() > 0)
> return true;
> + /* Is there any swapcache pages to reclaim? */
> + if (total_swapcache_pages() > 0) {
> + sc->swapcache_only = 1;
> + return true;
> + }
> } else {
> /* Is the memcg below its swap limit? */
> if (mem_cgroup_get_nr_swap_pages(memcg) > 0)
> return true;
> + /* Is there any swapcache pages in memcg to reclaim? */
> + if (mem_cgroup_get_nr_swapcache_pages(memcg) > 0) {
> + sc->swapcache_only = 1;
> + return true;
> + }
> }
>
> /*
> @@ -2280,6 +2293,19 @@ static bool skip_cma(struct folio *folio, struct scan_control *sc)
> }
> #endif
>
> +static bool skip_isolate(struct folio *folio, struct scan_control *sc,
> + enum lru_list lru)
> +{
> + if (folio_zonenum(folio) > sc->reclaim_idx)
> + return true;
> + if (skip_cma(folio, sc))
> + return true;
> + if (unlikely(sc->swapcache_only && !is_file_lru(lru) &&
> + !folio_test_swapcache(folio)))
> + return true;
> + return false;
> +}
> +
> /*
> * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
> *
> @@ -2326,8 +2352,7 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
> nr_pages = folio_nr_pages(folio);
> total_scan += nr_pages;
>
> - if (folio_zonenum(folio) > sc->reclaim_idx ||
> - skip_cma(folio, sc)) {
> + if (skip_isolate(folio, sc, lru)) {
> nr_skipped[folio_zonenum(folio)] += nr_pages;
> move_to = &folios_skipped;
> goto move;
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space
@ 2023-08-29 2:41 Liu Shixin
2023-08-29 2:12 ` Huang, Ying
2023-08-29 15:23 ` Yosry Ahmed
0 siblings, 2 replies; 4+ messages in thread
From: Liu Shixin @ 2023-08-29 2:41 UTC (permalink / raw)
To: Yosry Ahmed, Huang Ying, Michal Hocko, Johannes Weiner,
Roman Gushchin, Shakeel Butt, Muchun Song, Andrew Morton,
wangkefeng.wang
Cc: linux-kernel, cgroups, linux-mm, Liu Shixin
When spaces of swap devices are exhausted, only file pages can be reclaimed.
But there are still some swapcache pages in anon lru list. This can lead
to a premature out-of-memory.
The problem is found with such step:
Firstly, set a 9MB disk swap space, then create a cgroup with 10MB
memory limit, then runs an program to allocates about 15MB memory.
The problem occurs occasionally, which may need about 100 times.
Fix it by checking number of swapcache pages in can_reclaim_anon_pages().
If the number is not zero, return true either. Moreover, add a new bit
swapcache_only in struct scan_control to skip isolating anon pages that
are not swapcache when only swapcache pages can be reclaimed to accelerate
reclaim efficiency.
Link: https://lore.kernel.org/linux-mm/14e15f31-f3d3-4169-8ed9-fb36e57cf578@huawei.com/
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Tested-by: Yosry Ahmed <yosryahmed@google.com>
---
include/linux/swap.h | 6 ++++++
mm/memcontrol.c | 8 ++++++++
mm/vmscan.c | 29 +++++++++++++++++++++++++++--
3 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 456546443f1f..0318e918bfa4 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -669,6 +669,7 @@ static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_p
}
extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
+extern long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg);
extern bool mem_cgroup_swap_full(struct folio *folio);
#else
static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
@@ -691,6 +692,11 @@ static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
return get_nr_swap_pages();
}
+static inline long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
+{
+ return total_swapcache_pages();
+}
+
static inline bool mem_cgroup_swap_full(struct folio *folio)
{
return vm_swap_full();
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e8ca4bdcb03c..c465829db92b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -7567,6 +7567,14 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
return nr_swap_pages;
}
+long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
+{
+ if (mem_cgroup_disabled())
+ return total_swapcache_pages();
+
+ return memcg_page_state(memcg, NR_SWAPCACHE);
+}
+
bool mem_cgroup_swap_full(struct folio *folio)
{
struct mem_cgroup *memcg;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1080209a568b..e73e2df8828d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -137,6 +137,9 @@ struct scan_control {
/* Always discard instead of demoting to lower tier memory */
unsigned int no_demotion:1;
+ /* Swap space is exhausted, only reclaim swapcache for anon LRU */
+ unsigned int swapcache_only:1;
+
/* Allocation order */
s8 order;
@@ -613,10 +616,20 @@ static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg,
*/
if (get_nr_swap_pages() > 0)
return true;
+ /* Is there any swapcache pages to reclaim? */
+ if (total_swapcache_pages() > 0) {
+ sc->swapcache_only = 1;
+ return true;
+ }
} else {
/* Is the memcg below its swap limit? */
if (mem_cgroup_get_nr_swap_pages(memcg) > 0)
return true;
+ /* Is there any swapcache pages in memcg to reclaim? */
+ if (mem_cgroup_get_nr_swapcache_pages(memcg) > 0) {
+ sc->swapcache_only = 1;
+ return true;
+ }
}
/*
@@ -2280,6 +2293,19 @@ static bool skip_cma(struct folio *folio, struct scan_control *sc)
}
#endif
+static bool skip_isolate(struct folio *folio, struct scan_control *sc,
+ enum lru_list lru)
+{
+ if (folio_zonenum(folio) > sc->reclaim_idx)
+ return true;
+ if (skip_cma(folio, sc))
+ return true;
+ if (unlikely(sc->swapcache_only && !is_file_lru(lru) &&
+ !folio_test_swapcache(folio)))
+ return true;
+ return false;
+}
+
/*
* Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
*
@@ -2326,8 +2352,7 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
nr_pages = folio_nr_pages(folio);
total_scan += nr_pages;
- if (folio_zonenum(folio) > sc->reclaim_idx ||
- skip_cma(folio, sc)) {
+ if (skip_isolate(folio, sc, lru)) {
nr_skipped[folio_zonenum(folio)] += nr_pages;
move_to = &folios_skipped;
goto move;
--
2.25.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space
2023-08-29 2:41 [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space Liu Shixin
2023-08-29 2:12 ` Huang, Ying
@ 2023-08-29 15:23 ` Yosry Ahmed
2023-08-30 1:51 ` Liu Shixin
1 sibling, 1 reply; 4+ messages in thread
From: Yosry Ahmed @ 2023-08-29 15:23 UTC (permalink / raw)
To: Liu Shixin
Cc: Huang Ying, Michal Hocko, Johannes Weiner, Roman Gushchin,
Shakeel Butt, Muchun Song, Andrew Morton, wangkefeng.wang,
linux-kernel, cgroups, linux-mm
On Mon, Aug 28, 2023 at 6:46 PM Liu Shixin <liushixin2@huawei.com> wrote:
>
> When spaces of swap devices are exhausted, only file pages can be reclaimed.
> But there are still some swapcache pages in anon lru list. This can lead
> to a premature out-of-memory.
>
> The problem is found with such step:
>
> Firstly, set a 9MB disk swap space, then create a cgroup with 10MB
> memory limit, then runs an program to allocates about 15MB memory.
>
> The problem occurs occasionally, which may need about 100 times.
The reproducer I used in v2 reproduces this very reliably and simply,
could you link to it instead?
https://lore.kernel.org/lkml/CAJD7tkZAfgncV+KbKr36=eDzMnT=9dZOT0dpMWcurHLr6Do+GA@mail.gmail.com/
>
> Fix it by checking number of swapcache pages in can_reclaim_anon_pages().
> If the number is not zero, return true either. Moreover, add a new bit
> swapcache_only in struct scan_control to skip isolating anon pages that
> are not swapcache when only swapcache pages can be reclaimed to accelerate
> reclaim efficiency.
>
> Link: https://lore.kernel.org/linux-mm/14e15f31-f3d3-4169-8ed9-fb36e57cf578@huawei.com/
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>
> Tested-by: Yosry Ahmed <yosryahmed@google.com>
Usually people add the difference from the previous version to make it
easy to know what changed.
I still prefer to add NR_SWAPCACHE to memcg1_stats. Anyway, the code
looks good to me. With the updated reproducer link feel free to add:
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
> ---
> include/linux/swap.h | 6 ++++++
> mm/memcontrol.c | 8 ++++++++
> mm/vmscan.c | 29 +++++++++++++++++++++++++++--
> 3 files changed, 41 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 456546443f1f..0318e918bfa4 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -669,6 +669,7 @@ static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_p
> }
>
> extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
> +extern long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg);
> extern bool mem_cgroup_swap_full(struct folio *folio);
> #else
> static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
> @@ -691,6 +692,11 @@ static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
> return get_nr_swap_pages();
> }
>
> +static inline long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
> +{
> + return total_swapcache_pages();
> +}
> +
> static inline bool mem_cgroup_swap_full(struct folio *folio)
> {
> return vm_swap_full();
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index e8ca4bdcb03c..c465829db92b 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -7567,6 +7567,14 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
> return nr_swap_pages;
> }
>
> +long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
> +{
> + if (mem_cgroup_disabled())
> + return total_swapcache_pages();
> +
> + return memcg_page_state(memcg, NR_SWAPCACHE);
> +}
> +
> bool mem_cgroup_swap_full(struct folio *folio)
> {
> struct mem_cgroup *memcg;
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 1080209a568b..e73e2df8828d 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -137,6 +137,9 @@ struct scan_control {
> /* Always discard instead of demoting to lower tier memory */
> unsigned int no_demotion:1;
>
> + /* Swap space is exhausted, only reclaim swapcache for anon LRU */
> + unsigned int swapcache_only:1;
> +
> /* Allocation order */
> s8 order;
>
> @@ -613,10 +616,20 @@ static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg,
> */
> if (get_nr_swap_pages() > 0)
> return true;
> + /* Is there any swapcache pages to reclaim? */
> + if (total_swapcache_pages() > 0) {
> + sc->swapcache_only = 1;
> + return true;
> + }
> } else {
> /* Is the memcg below its swap limit? */
> if (mem_cgroup_get_nr_swap_pages(memcg) > 0)
> return true;
> + /* Is there any swapcache pages in memcg to reclaim? */
> + if (mem_cgroup_get_nr_swapcache_pages(memcg) > 0) {
> + sc->swapcache_only = 1;
> + return true;
> + }
> }
>
> /*
> @@ -2280,6 +2293,19 @@ static bool skip_cma(struct folio *folio, struct scan_control *sc)
> }
> #endif
>
> +static bool skip_isolate(struct folio *folio, struct scan_control *sc,
> + enum lru_list lru)
> +{
> + if (folio_zonenum(folio) > sc->reclaim_idx)
> + return true;
> + if (skip_cma(folio, sc))
> + return true;
> + if (unlikely(sc->swapcache_only && !is_file_lru(lru) &&
> + !folio_test_swapcache(folio)))
> + return true;
> + return false;
> +}
> +
> /*
> * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
> *
> @@ -2326,8 +2352,7 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
> nr_pages = folio_nr_pages(folio);
> total_scan += nr_pages;
>
> - if (folio_zonenum(folio) > sc->reclaim_idx ||
> - skip_cma(folio, sc)) {
> + if (skip_isolate(folio, sc, lru)) {
> nr_skipped[folio_zonenum(folio)] += nr_pages;
> move_to = &folios_skipped;
> goto move;
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space
2023-08-29 15:23 ` Yosry Ahmed
@ 2023-08-30 1:51 ` Liu Shixin
0 siblings, 0 replies; 4+ messages in thread
From: Liu Shixin @ 2023-08-30 1:51 UTC (permalink / raw)
To: Yosry Ahmed
Cc: Huang Ying, Michal Hocko, Johannes Weiner, Roman Gushchin,
Shakeel Butt, Muchun Song, Andrew Morton, wangkefeng.wang,
linux-kernel, cgroups, linux-mm
On 2023/8/29 23:23, Yosry Ahmed wrote:
> On Mon, Aug 28, 2023 at 6:46 PM Liu Shixin <liushixin2@huawei.com> wrote:
>> When spaces of swap devices are exhausted, only file pages can be reclaimed.
>> But there are still some swapcache pages in anon lru list. This can lead
>> to a premature out-of-memory.
>>
>> The problem is found with such step:
>>
>> Firstly, set a 9MB disk swap space, then create a cgroup with 10MB
>> memory limit, then runs an program to allocates about 15MB memory.
>>
>> The problem occurs occasionally, which may need about 100 times.
> The reproducer I used in v2 reproduces this very reliably and simply,
> could you link to it instead?
>
> https://lore.kernel.org/lkml/CAJD7tkZAfgncV+KbKr36=eDzMnT=9dZOT0dpMWcurHLr6Do+GA@mail.gmail.com/
OK
>
>> Fix it by checking number of swapcache pages in can_reclaim_anon_pages().
>> If the number is not zero, return true either. Moreover, add a new bit
>> swapcache_only in struct scan_control to skip isolating anon pages that
>> are not swapcache when only swapcache pages can be reclaimed to accelerate
>> reclaim efficiency.
>>
>> Link: https://lore.kernel.org/linux-mm/14e15f31-f3d3-4169-8ed9-fb36e57cf578@huawei.com/
>> Signed-off-by: Liu Shixin <liushixin2@huawei.com>
>> Tested-by: Yosry Ahmed <yosryahmed@google.com>
> Usually people add the difference from the previous version to make it
> easy to know what changed.
>
> I still prefer to add NR_SWAPCACHE to memcg1_stats. Anyway, the code
> looks good to me. With the updated reproducer link feel free to add:
>
> Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Thanks,
>
>> ---
>> include/linux/swap.h | 6 ++++++
>> mm/memcontrol.c | 8 ++++++++
>> mm/vmscan.c | 29 +++++++++++++++++++++++++++--
>> 3 files changed, 41 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/linux/swap.h b/include/linux/swap.h
>> index 456546443f1f..0318e918bfa4 100644
>> --- a/include/linux/swap.h
>> +++ b/include/linux/swap.h
>> @@ -669,6 +669,7 @@ static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_p
>> }
>>
>> extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
>> +extern long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg);
>> extern bool mem_cgroup_swap_full(struct folio *folio);
>> #else
>> static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
>> @@ -691,6 +692,11 @@ static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
>> return get_nr_swap_pages();
>> }
>>
>> +static inline long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
>> +{
>> + return total_swapcache_pages();
>> +}
>> +
>> static inline bool mem_cgroup_swap_full(struct folio *folio)
>> {
>> return vm_swap_full();
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index e8ca4bdcb03c..c465829db92b 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -7567,6 +7567,14 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
>> return nr_swap_pages;
>> }
>>
>> +long mem_cgroup_get_nr_swapcache_pages(struct mem_cgroup *memcg)
>> +{
>> + if (mem_cgroup_disabled())
>> + return total_swapcache_pages();
>> +
>> + return memcg_page_state(memcg, NR_SWAPCACHE);
>> +}
>> +
>> bool mem_cgroup_swap_full(struct folio *folio)
>> {
>> struct mem_cgroup *memcg;
>> diff --git a/mm/vmscan.c b/mm/vmscan.c
>> index 1080209a568b..e73e2df8828d 100644
>> --- a/mm/vmscan.c
>> +++ b/mm/vmscan.c
>> @@ -137,6 +137,9 @@ struct scan_control {
>> /* Always discard instead of demoting to lower tier memory */
>> unsigned int no_demotion:1;
>>
>> + /* Swap space is exhausted, only reclaim swapcache for anon LRU */
>> + unsigned int swapcache_only:1;
>> +
>> /* Allocation order */
>> s8 order;
>>
>> @@ -613,10 +616,20 @@ static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg,
>> */
>> if (get_nr_swap_pages() > 0)
>> return true;
>> + /* Is there any swapcache pages to reclaim? */
>> + if (total_swapcache_pages() > 0) {
>> + sc->swapcache_only = 1;
>> + return true;
>> + }
>> } else {
>> /* Is the memcg below its swap limit? */
>> if (mem_cgroup_get_nr_swap_pages(memcg) > 0)
>> return true;
>> + /* Is there any swapcache pages in memcg to reclaim? */
>> + if (mem_cgroup_get_nr_swapcache_pages(memcg) > 0) {
>> + sc->swapcache_only = 1;
>> + return true;
>> + }
>> }
>>
>> /*
>> @@ -2280,6 +2293,19 @@ static bool skip_cma(struct folio *folio, struct scan_control *sc)
>> }
>> #endif
>>
>> +static bool skip_isolate(struct folio *folio, struct scan_control *sc,
>> + enum lru_list lru)
>> +{
>> + if (folio_zonenum(folio) > sc->reclaim_idx)
>> + return true;
>> + if (skip_cma(folio, sc))
>> + return true;
>> + if (unlikely(sc->swapcache_only && !is_file_lru(lru) &&
>> + !folio_test_swapcache(folio)))
>> + return true;
>> + return false;
>> +}
>> +
>> /*
>> * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
>> *
>> @@ -2326,8 +2352,7 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
>> nr_pages = folio_nr_pages(folio);
>> total_scan += nr_pages;
>>
>> - if (folio_zonenum(folio) > sc->reclaim_idx ||
>> - skip_cma(folio, sc)) {
>> + if (skip_isolate(folio, sc, lru)) {
>> nr_skipped[folio_zonenum(folio)] += nr_pages;
>> move_to = &folios_skipped;
>> goto move;
>> --
>> 2.25.1
>>
> .
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-08-30 1:51 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-08-29 2:41 [PATCH v4] mm: vmscan: try to reclaim swapcache pages if no swap space Liu Shixin
2023-08-29 2:12 ` Huang, Ying
2023-08-29 15:23 ` Yosry Ahmed
2023-08-30 1:51 ` Liu Shixin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox