linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: 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: Re: [PATCH 1/2] mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked
Date: Sat, 24 Dec 2016 11:51:13 -0800	[thread overview]
Message-ID: <CA+55aFzG_vTFf5_i-no5PSYPMyGv_N=ufz0yRte=cZXFoEwLpQ@mail.gmail.com> (raw)
In-Reply-To: <20161221151951.16396-2-npiggin@gmail.com>

Nick,
mind adding a changelog and a sign-off for these two patches?

I'd like to apply at least the first one asap, just to get as much
verification of the page flag bits as possible.

             Linus

On Wed, Dec 21, 2016 at 7:19 AM, Nicholas Piggin <npiggin@gmail.com> wrote:
> ---
>  include/linux/page-flags.h     | 24 ++++++++++++++++--------
>  include/trace/events/mmflags.h |  1 -
>  2 files changed, 16 insertions(+), 9 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"    },              \
> --
> 2.11.0
>

  parent reply	other threads:[~2016-12-24 19:51 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
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 [this message]
2016-12-21 15:19 ` [PATCH 2/2] mm: add PageWaiters bit to indicate waitqueue should be checked Nicholas Piggin
2016-12-21 17:30 ` [PATCH 0/2] respin of PageWaiters patch Linus Torvalds
2016-12-25  3:00 [PATCH 0/2] PageWaiters again Nicholas Piggin
2016-12-25  3:00 ` [PATCH 1/2] mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked Nicholas Piggin
2016-12-25  5:13   ` Hugh Dickins

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='CA+55aFzG_vTFf5_i-no5PSYPMyGv_N=ufz0yRte=cZXFoEwLpQ@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --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=npiggin@gmail.com \
    --cc=peterz@infradead.org \
    --cc=rpeterso@redhat.com \
    --cc=swhiteho@redhat.com \
    --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).