Messages in this thread | | | Date | Tue, 1 Nov 2011 15:04:48 +0000 | From | Mel Gorman <> | Subject | Re: [PATCH 2/9] mm: alloc_contig_freed_pages() added |
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On Sun, Oct 23, 2011 at 09:05:05PM -0700, Michal Nazarewicz wrote: > > On Thu, Oct 06, 2011 at 03:54:42PM +0200, Marek Szyprowski wrote: > >> This commit introduces alloc_contig_freed_pages() function > >> which allocates (ie. removes from buddy system) free pages > >> in range. Caller has to guarantee that all pages in range > >> are in buddy system. > > On Tue, 18 Oct 2011 05:21:09 -0700, Mel Gorman <mel@csn.ul.ie> wrote: > > Straight away, I'm wondering why you didn't use > > mm/compaction.c#isolate_freepages() > > Does the below look like a step in the right direction? > > It basically moves isolate_freepages_block() to page_alloc.c (changing
For the purposes of review, have a separate patch for moving isolate_freepages_block to another file that does not alter the function in any way. When the function is updated in a follow-on patch, it'll be far easier to see what has changed.
page_isolation.c may also be a better fit than page_alloc.c
As it is, the patch for isolate_freepages_block is almost impossible to read because it's getting munged with existing code that is already in page_alloc.c . About all I caught from it is that scannedp does not have a type. It defaults to unsigned int but it's unnecessarily obscure.
> it name to isolate_freepages_range()) and changes it so that depending > on arguments it treats holes (either invalid PFN or non-free page) as > errors so that CMA can use it. >
I haven't actually read the function because it's too badly mixed with page_alloc.c code but this description fits what I'm looking for.
> It also accepts a range rather then just assuming a single pageblock > thus the change moves range calculation in compaction.c from > isolate_freepages_block() up to isolate_freepages(). > > The change also modifies spilt_free_page() so that it does not try to > change pageblock's migrate type if current migrate type is ISOLATE or > CMA. >
This is fine. Later, the flags that determine what happens to pageblocks may be placed in compact_control.
> --- > include/linux/mm.h | 1 - > include/linux/page-isolation.h | 4 +- > mm/compaction.c | 73 +++-------------------- > mm/internal.h | 5 ++ > mm/page_alloc.c | 128 +++++++++++++++++++++++++--------------- > 5 files changed, 95 insertions(+), 116 deletions(-) >
I confess I didn't read closely because of the mess in page_alloc.c but the intent seems fine. Hopefully there will be a new version of CMA posted that will be easier to review.
Thanks
-- Mel Gorman SUSE Labs
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