From: Nicholas Piggin <npiggin@gmail.com> To: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com>, Dave Hansen <dave.hansen@linux.intel.com>, Bob Peterson <rpeterso@redhat.com>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Steven Whitehouse <swhiteho@redhat.com>, Andrew Lutomirski <luto@kernel.org>, Andreas Gruenbacher <agruenba@redhat.com>, Peter Zijlstra <peterz@infradead.org>, linux-mm <linux-mm@kvack.org>, Mel Gorman <mgorman@techsingularity.net> Subject: [PATCH 1/2] mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked Date: Sun, 25 Dec 2016 13:00:29 +1000 [thread overview] Message-ID: <20161225030030.23219-2-npiggin@gmail.com> (raw) In-Reply-To: <20161225030030.23219-1-npiggin@gmail.com> A page is not added to the swap cache without being swap backed, so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- include/linux/page-flags.h | 24 ++++++++++++++++-------- include/trace/events/mmflags.h | 1 - mm/memory-failure.c | 4 +--- mm/migrate.c | 14 ++++++++------ 4 files changed, 25 insertions(+), 18 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 74e4dda91238..a57c909a15e4 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -87,7 +87,6 @@ enum pageflags { PG_private_2, /* If pagecache, has fs aux data */ PG_writeback, /* Page is under writeback */ PG_head, /* A head page */ - PG_swapcache, /* Swap page: swp_entry_t in private */ PG_mappedtodisk, /* Has blocks allocated on-disk */ PG_reclaim, /* To be reclaimed asap */ PG_swapbacked, /* Page is backed by RAM/swap */ @@ -110,6 +109,9 @@ enum pageflags { /* Filesystems */ PG_checked = PG_owner_priv_1, + /* SwapBacked */ + PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ + /* Two page bits are conscripted by FS-Cache to maintain local caching * state. These bits are set on pages belonging to the netfs's inodes * when those inodes are being locally cached. @@ -314,7 +316,13 @@ PAGEFLAG_FALSE(HighMem) #endif #ifdef CONFIG_SWAP -PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) +static __always_inline int PageSwapCache(struct page *page) +{ + return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); + +} +SETPAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) +CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) #else PAGEFLAG_FALSE(SwapCache) #endif @@ -701,12 +709,12 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) * Flags checked when a page is freed. Pages being freed should not have * these flags set. It they are, there is a problem. */ -#define PAGE_FLAGS_CHECK_AT_FREE \ - (1UL << PG_lru | 1UL << PG_locked | \ - 1UL << PG_private | 1UL << PG_private_2 | \ - 1UL << PG_writeback | 1UL << PG_reserved | \ - 1UL << PG_slab | 1UL << PG_swapcache | 1UL << PG_active | \ - 1UL << PG_unevictable | __PG_MLOCKED) +#define PAGE_FLAGS_CHECK_AT_FREE \ + (1UL << PG_lru | 1UL << PG_locked | \ + 1UL << PG_private | 1UL << PG_private_2 | \ + 1UL << PG_writeback | 1UL << PG_reserved | \ + 1UL << PG_slab | 1UL << PG_active | \ + 1UL << PG_unevictable | __PG_MLOCKED) /* * Flags checked when a page is prepped for return by the page allocator. diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index 5a81ab48a2fb..30c2adbdebe8 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -95,7 +95,6 @@ {1UL << PG_private_2, "private_2" }, \ {1UL << PG_writeback, "writeback" }, \ {1UL << PG_head, "head" }, \ - {1UL << PG_swapcache, "swapcache" }, \ {1UL << PG_mappedtodisk, "mappedtodisk" }, \ {1UL << PG_reclaim, "reclaim" }, \ {1UL << PG_swapbacked, "swapbacked" }, \ diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 19e796d36a62..f283c7e0a2a3 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -764,12 +764,11 @@ static int me_huge_page(struct page *p, unsigned long pfn) */ #define dirty (1UL << PG_dirty) -#define sc (1UL << PG_swapcache) +#define sc ((1UL << PG_swapcache) | (1UL << PG_swapbacked)) #define unevict (1UL << PG_unevictable) #define mlock (1UL << PG_mlocked) #define writeback (1UL << PG_writeback) #define lru (1UL << PG_lru) -#define swapbacked (1UL << PG_swapbacked) #define head (1UL << PG_head) #define slab (1UL << PG_slab) #define reserved (1UL << PG_reserved) @@ -819,7 +818,6 @@ static struct page_state { #undef mlock #undef writeback #undef lru -#undef swapbacked #undef head #undef slab #undef reserved diff --git a/mm/migrate.c b/mm/migrate.c index 0ed24b1fa77b..87f4d0f81819 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -466,13 +466,15 @@ int migrate_page_move_mapping(struct address_space *mapping, */ newpage->index = page->index; newpage->mapping = page->mapping; - if (PageSwapBacked(page)) - __SetPageSwapBacked(newpage); - get_page(newpage); /* add cache reference */ - if (PageSwapCache(page)) { - SetPageSwapCache(newpage); - set_page_private(newpage, page_private(page)); + if (PageSwapBacked(page)) { + __SetPageSwapBacked(newpage); + if (PageSwapCache(page)) { + SetPageSwapCache(newpage); + set_page_private(newpage, page_private(page)); + } + } else { + VM_BUG_ON_PAGE(PageSwapCache(page), page); } /* Move dirty while page refs frozen and newpage not yet exposed */ -- 2.11.0
next prev parent reply other threads:[~2016-12-25 3:00 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-12-25 3:00 [PATCH 0/2] PageWaiters again Nicholas Piggin 2016-12-25 3:00 ` Nicholas Piggin [this message] 2016-12-25 5:13 ` [PATCH 1/2] mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked Hugh Dickins 2016-12-25 3:00 ` [PATCH 2/2] mm: add PageWaiters indicating tasks are waiting for a page bit Nicholas Piggin 2016-12-25 21:51 ` Linus Torvalds 2016-12-26 1:16 ` Nicholas Piggin 2016-12-26 19:07 ` Linus Torvalds 2016-12-27 11:19 ` Nicholas Piggin 2016-12-27 18:58 ` Linus Torvalds 2016-12-27 19:23 ` Linus Torvalds 2016-12-27 19:24 ` Linus Torvalds 2016-12-27 19:40 ` Linus Torvalds 2016-12-27 20:17 ` Linus Torvalds 2016-12-28 3:53 ` Nicholas Piggin 2016-12-28 19:17 ` Linus Torvalds 2016-12-29 4:08 ` Nicholas Piggin 2016-12-29 4:16 ` Linus Torvalds 2016-12-29 5:26 ` Nicholas Piggin 2017-01-03 10:24 ` Mel Gorman 2017-01-03 12:29 ` Nicholas Piggin 2017-01-03 17:18 ` Mel Gorman 2016-12-29 22:16 ` [PATCH] mm/filemap: fix parameters to test_bit() Olof Johansson -- strict thread matches above, loose matches on Subject: below -- 2016-12-21 15:19 [PATCH 0/2] respin of PageWaiters patch Nicholas Piggin 2016-12-21 15:19 ` [PATCH 1/2] mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked Nicholas Piggin 2016-12-22 19:55 ` Hugh Dickins 2016-12-25 1:00 ` Nicholas Piggin 2016-12-24 19:51 ` Linus Torvalds
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20161225030030.23219-2-npiggin@gmail.com \ --to=npiggin@gmail.com \ --cc=agruenba@redhat.com \ --cc=dave.hansen@linux.intel.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=luto@kernel.org \ --cc=mgorman@techsingularity.net \ --cc=peterz@infradead.org \ --cc=rpeterso@redhat.com \ --cc=swhiteho@redhat.com \ --cc=torvalds@linux-foundation.org \ --subject='Re: [PATCH 1/2] mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).