Hello Cyrill, On Thu, Aug 22, 2013 at 09:49:19AM +0400, Cyrill Gorcunov wrote: > On Wed, Aug 21, 2013 at 04:42:53PM -0700, Andi Kleen wrote: > > Cyrill Gorcunov <gorcu...@gmail.com> writes: > > > > > > Hi all, I worked on patch which would not touch PSE bit for dirty page > > > tracking and the result is not that good: > > > > > > - 2level pages now always page dirty if page is swapped in and out, > > > because > > > there is no space left in PTE (other than PSE bit) > > > > Maybe just don't support soft dirty for 2 level page tables? > > > > 2 level page tables should be really on the way out anyways, as they > > have severe limits and do not support NX. With 3 levels there is enough > > space. > > Look, good thing is that 7th bit also available on the 4level pages > (ie x86-64) without additional code modification, that's why I picked > it in first place. I prepared the patch locally which doesn't use > pse bit for tracking but it only makes code more complex.
I'm not sure you read this thread. http://comments.gmane.org/gmane.linux.kernel.mm/101756 In summary, I'd like to use it to track sub-ranges of some processes. I already had a time to investigate and it enhanced our workload x2 on ARM so I'd like to expand the concept for more general purpose. For it, arch-specific stuff would be hurdle for port. So, I support your non-arch-specific solutions. Just FYI. Such future plan shouldn't force you. Thanks. -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
