On Tue, Aug 29, 2017 at 11:16:18AM +0200, Vlastimil Babka wrote: > On 08/24/2017 08:36 AM, js1304@xxxxxxxxx wrote: > > From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > > > > 0. History > > > > This patchset is the follow-up of the discussion about the > > "Introduce ZONE_CMA (v7)" [1]. Please reference it if more information > > is needed. > > > > [...] > > > > > [1]: lkml.kernel.org/r/1491880640-9944-1-git-send-email-iamjoonsoo.kim@xxxxxxx > > [2]: https://lkml.org/lkml/2014/10/15/623 > > [3]: http://www.spinics.net/lists/linux-mm/msg100562.html > > > > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> > > Acked-by: Vlastimil Babka <vbabka@xxxxxxx> > > The previous version has introduced ZONE_CMA, so I would think switching > to ZONE_MOVABLE is enough to drop previous reviews. Perhaps most of the > code involved is basically the same, though? Yes, most of the code involved is the same. I considered to drop previous review tags but most of the code and concept is the same so I decide to keep review tags. I should mention it in cover-letter but I forgot to mention it. Sorry about that. > Anyway I checked the current patch and did some basic tests with qemu, > so you can keep my ack. Thanks! > > BTW, if we dropped NR_FREE_CMA_PAGES, could we also drop MIGRATE_CMA and > related hooks? Is that counter really that useful as it works right now? > It will decrease both by CMA allocations (which has to be explicitly > freed) and by movable allocations (which can be migrated). What if only > CMA alloc/release touched it? I think that NR_FREE_CMA_PAGES would not be as useful as previous. We can remove it. However, removing MIGRATE_CMA has a problem. There is an usecase to check if the page comes from the CMA area or not. See check_page_span() in mm/usercopy.c. I can implement it differently by iterating whole CMA area and finding the match, but I'm not sure it's performance effect. I guess that it would be marginal. Anyway, I'd like not to cause any side-effect now. After patches are settle down on mainline, I will try to remove them as you suggested. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
