Messages in this thread | | | Date | Wed, 29 Dec 2021 15:53:35 +0100 | From | Oscar Salvador <> | Subject | Re: [PATCH] mm/page_isolation: unset migratetype directly for non Buddy page |
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On Wed, Dec 29, 2021 at 11:36:49AM +0800, Chen Wandun wrote: > There is no need to try to move_freepages_block for pages that is not > in buddy in function unset_migratetype_isolate, it can directly set > migrate type.
The above could benefit from some rephrasing, someting along these lines maybe?
"In unset_migratetype_isolate(), we can bypass the call to move_freepages_block() for non-buddy pages"
> > It will save a few cpu cycles for some situations such as cma and > hugetlb when allocating continue pages, in these situation function > alloc_contig_pages will be called. > > alloc_contig_pages > __alloc_contig_migrate_range > isolate_freepages_range ==> pages has been remove from buddy > undo_isolate_page_range > unset_migratetype_isolate ==> can directly set migratetype > > Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock") > Signed-off-by: Chen Wandun <chenwandun@huawei.com>
I am ok with the "fix", but I don't think this deserves a Fixes tag. Sure, it can spare some cpu cycles, but besides that, there is no harm in the actual code unless I missed something.
Others might feel stronger about that.
Reviewed-by: Oscar Salvador <osalvador@suse.de>
-- Oscar Salvador SUSE Labs
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