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WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <87il9053zo.fsf@yhuang6-desk2.ccr.corp.intel.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.24] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500009.china.huawei.com (7.185.36.225) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: F1A0140016 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: 7m5awu4jxaey3gdu5ja5crq3ruhx69jo X-HE-Tag: 1693206685-590625 X-HE-Meta: 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 l26gdQ1E e4rTgo8HytXHbNAerjxVT4e+1zZ5svfZvSio0AcoDbXWxlM+AHz1XW6Rcy2FMnV4+QZeRUkOQSzL0vpfzp+QcFbjBxRHpdyVtDO5xtO3Lduk2vGTKZ9JnZYqPvzrqFN3PhnWJMCDh1Um9PndV+LUJiw0wkS1xm386+YllPTw5+BfgLveF0SRkWNrCODuGREpE3COOJqTWD/U4uPSslJRQO5prMdWf0nBkYhcnMSbfkraxNMM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2023/8/28 9:51, Huang, Ying wrote: > Liu Shixin 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. >> >> This problem can be fixed by checking number of swapcache pages in >> can_reclaim_anon_pages(). >> >> Add a new bit swapcache_only in struct scan_control to skip isolating anon >> pages that are not in the swap cache when only swap cache can be reclaimed. > Better to describe how you test the patch and test results. OK, I will add the infomation. > >> Signed-off-by: Liu Shixin >> --- >> 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 7c33c5b653ef..5cb4adf6642b 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))) > Just > > if (unlikely(sc->swapcache_only && !folio_test_swapcache(folio))) > > is enough. That would results the file pages to be skipped too, but what expected is to skip non-swapcache pages in anon lru list. So I think the condition !is_file_lru(lru) is required. Thanks, > >> + 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; > -- > Best Regards, > Huang, Ying > . >