On Thu, Jul 26, 2012 at 01:42:26PM -0400, Rik van Riel wrote: > On 07/23/2012 12:04 AM, Hugh Dickins wrote: > > >Please don't be upset if I say that I don't like either of your patches. > >Mainly for obvious reasons - I don't like Mel's because anything with > >trylock retries and nested spinlocks worries me before I can even start > >to think about it; and I don't like Michal's for the same reason as Mel, > >that it spreads more change around in common paths than we would like. > > I have a naive question. > > In huge_pmd_share, we protect ourselves by taking > the mapping->i_mmap_mutex. > > Is there any reason we could not take the i_mmap_mutex > in the huge_pmd_unshare path? > We do, in 3.4 at least - callers of __unmap_hugepage_range hold the i_mmap_mutex. Locking changes in mmotm and there is a patch there that needs to be reverted. What tree are you looking at? -- Mel Gorman SUSE Labs -- 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>