V2 -> V3:

+ rebase to 23-mm1 atop RvR's split lru series

+ fix page flags macros for *PageMlocked() when not configured.

+ ensure lru_add_drain_all() runs on all cpus when NORECLAIM_MLOCK

  configured.  Was just for NUMA.
V1 -> V2:

+ moved this patch [and related patches] up to right after

  ramdisk/ramfs and SHM_LOCKed patches.

+ add [back] missing put_page() in putback_lru_page().

  This solved page leakage as seen by stats in previous

  version.

+ fix up munlock_vma_page() to isolate page from lru

  before calling try_to_unlock().  Think I detected a

  race here.

+ use TestClearPageMlock() on old page in migrate.c's

  migrate_page_copy() to clean up old page.

+ live dangerously:  remove TestSetPageLocked() in

  is_mlocked_vma()--should only be called on new pages in

  the fault path--iff we chose to cull there [later patch].

+ Add PG_mlocked to free_pages_check() etc to detect mlock

  state mismanagement.

  NOTE:  temporarily [???] commented out--tripping over it

  under load.  Why?
Rework of a patch by Nick Piggin -- part 1 of 2.
This patch:
1) defines the [CONFIG_]NORECLAIM_MLOCK sub-option and the

   stub version of the mlock/noreclaim APIs when it's

   not configured.  Depends on [CONFIG_]NORECLAIM.
2) add yet another page flag--PG_mlocked--to indicate that

   the page is locked for efficient testing in vmscan and,

   optionally, fault path.  This allows early culling of

   nonreclaimable pages, preventing them from getting to

   page_referenced()/try_to_unmap().  Also allows separate

   accounting of mlock'd pages, as Nick's original patch

   did.
   Uses a bit available only to 64-bit systems.
   Note:  Nick's original mlock patch used a PG_mlocked

   flag.  I had removed this in favor of the PG_noreclaim

   flag + an mlock_count [new page struct member].  I

   restored the PG_mlocked flag to eliminate the new

   count field.
3) add the mlock/noreclaim infrastructure to mm/mlock.c,

   with internal APIs in mm/internal.h.  This is a rework

...
[ message continues ]

Hi, Rik.
There is a some trivial mistake.

It can cause compile error.
 >@@ -665,7 +677,12 @@ static int prep_new_page(struct page *pa

 >

 > 	page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead |

 > 			1 << PG_referenced | 1 << PG_arch_1 |

 >-			1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);

 >+			1 << PG_owner_priv_1 | 1 << PG_mappedtodisk |

 >+#ifdef CONFIG_NORECLAIM_MLOCK

 >+//TODO take care of it here, for now.

 >+			1 << PG_mlocked

 >+#endif

 >+			);

 > 	set_page_private(page, 0);

 > 	set_page_refcounted(page);
we need to fix it.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c

index 78c3f94..f6d535f 100644

--- a/mm/page_alloc.c

+++ b/mm/page_alloc.c

@@ -677,10 +677,10 @@ static int prep_new_page(struct page *page, int

order, gfp_t gfp_flags)
   page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead |

       1 << PG_referenced | 1 << PG_arch_1 |

-     1 << PG_owner_priv_1 | 1 << PG_mappedtodisk |

+     1 << PG_owner_priv_1 | 1 << PG_mappedtodisk

  #ifdef CONFIG_NORECLAIM_MLOCK

  //TODO take care of it here, for now.

-     1 << PG_mlocked

+     | 1 << PG_mlocked

  #endif

       );

   set_page_private(page, 0);
Thanks,

barrios.

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On Wed, 05 Mar 2008 09:28:21 +0900
Thank you.  I have applied your fix.
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All rights reversed.

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