On Sun, 22 Jan 2006, Marcelo Tosatti wrote:
> Hi Mel,
>
> On Fri, Jan 20, 2006 at 11:54:55AM +0000, Mel Gorman wrote:
> >
> > This patch adds the core of the anti-fragmentation strategy. It works by
> > grouping related allocation types together. The idea is that large groups of
> > pages that may be reclaimed are placed near each other. The zone->free_area
> > list is broken into RCLM_TYPES number of lists.
> >
> > Signed-off-by: Mel Gorman <[email protected]>
> > Signed-off-by: Joel Schopp <[email protected]>
> > diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.16-rc1-mm1-001_antifrag_flags/include/linux/mmzone.h linux-2.6.16-rc1-mm1-002_fragcore/include/linux/mmzone.h
> > --- linux-2.6.16-rc1-mm1-001_antifrag_flags/include/linux/mmzone.h 2006-01-19 11:21:59.000000000 +0000
> > +++ linux-2.6.16-rc1-mm1-002_fragcore/include/linux/mmzone.h 2006-01-19 21:51:05.000000000 +0000
> > @@ -22,8 +22,16 @@
> > #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
> > #endif
> >
> > +#define RCLM_NORCLM 0
> > +#define RCLM_EASY 1
> > +#define RCLM_TYPES 2
> > +
> > +#define for_each_rclmtype_order(type, order) \
> > + for (order = 0; order < MAX_ORDER; order++) \
> > + for (type = 0; type < RCLM_TYPES; type++)
> > +
> > struct free_area {
> > - struct list_head free_list;
> > + struct list_head free_list[RCLM_TYPES];
> > unsigned long nr_free;
> > };
> >
> > diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.16-rc1-mm1-001_antifrag_flags/include/linux/page-flags.h linux-2.6.16-rc1-mm1-002_fragcore/include/linux/page-flags.h
> > --- linux-2.6.16-rc1-mm1-001_antifrag_flags/include/linux/page-flags.h 2006-01-19 11:21:59.000000000 +0000
> > +++ linux-2.6.16-rc1-mm1-002_fragcore/include/linux/page-flags.h 2006-01-19 21:51:05.000000000 +0000
> > @@ -76,6 +76,7 @@
> > #define PG_reclaim 17 /* To be reclaimed asap */
> > #define PG_nosave_free 18 /* Free, should not be written */
> > #define PG_uncached 19 /* Page has been mapped as uncached */
> > +#define PG_easyrclm 20 /* Page is in an easy reclaim block */
> >
> > /*
> > * Global page accounting. One instance per CPU. Only unsigned longs are
> > @@ -345,6 +346,12 @@ extern void __mod_page_state_offset(unsi
> > #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags)
> > #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags)
> >
> > +#define PageEasyRclm(page) test_bit(PG_easyrclm, &(page)->flags)
> > +#define SetPageEasyRclm(page) set_bit(PG_easyrclm, &(page)->flags)
> > +#define ClearPageEasyRclm(page) clear_bit(PG_easyrclm, &(page)->flags)
> > +#define __SetPageEasyRclm(page) __set_bit(PG_easyrclm, &(page)->flags)
> > +#define __ClearPageEasyRclm(page) __clear_bit(PG_easyrclm, &(page)->flags)
> > +
>
> You can't read/write to page->flags non-atomically, except when you
> guarantee that the page is not visible to other CPU's (eg at the very
> end of the page freeing code).
>
The helper PageEasyRclm is only used when either the spinlock is held or a
per-cpu page is being released so it should be safe. The Set and Clear
helpers are only used with a spinlock held.
> Please use atomic operations.
>
--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
