Re: [PATCH v2 2/2] mm: speed up mremap by 500x on large regions

2018-10-15 Thread Joel Fernandes
On Mon, Oct 15, 2018 at 10:18:14AM +0200, Martin Schwidefsky wrote: > On Mon, 15 Oct 2018 09:10:53 +0200 > Christian Borntraeger wrote: > > > On 10/12/2018 03:37 AM, Joel Fernandes (Google) wrote: > > > Android needs to mremap large regions of memory during memory management > > > related operati

Re: [PATCH 2/4] mm: speed up mremap by 500x on large regions (v2)

2018-10-15 Thread Joel Fernandes
On Mon, Oct 15, 2018 at 02:42:09AM -0700, Christoph Hellwig wrote: > On Fri, Oct 12, 2018 at 06:31:58PM -0700, Joel Fernandes (Google) wrote: > > Android needs to mremap large regions of memory during memory management > > related operations. > > Just curious: why? In Android we have a requiremen

Re: [PATCH 12/18] arch/tlb: Clean up simple architectures

2018-10-15 Thread Peter Zijlstra
On Fri, Oct 12, 2018 at 07:40:04PM +, Vineet Gupta wrote: > Very nice. Thx for doing this. > > Once you have redone this, please point me to a branch so I can give this a > spin. > I've always been interested in tracking down / optimizing the full TLB > flushes - > which ARC implements by si

Re: [PATCH v2 1/2] mtd: spi-nor: Add support of sst26wf* flash ICs protection ops

2018-10-15 Thread Eugeniy Paltsev
Hi! Maybe you have any comments or remarks about this patch? And if you don't could you please apply it. Thanks! On Mon, 2018-09-10 at 14:46 +0300, Eugeniy Paltsev wrote: > sst26wf flash series block protection implementation differs > from other SST series, so add specific implementation > flash

Re: [PATCH 2/4] mm: speed up mremap by 500x on large regions (v2)

2018-10-15 Thread Christoph Hellwig
On Fri, Oct 12, 2018 at 06:31:58PM -0700, Joel Fernandes (Google) wrote: > Android needs to mremap large regions of memory during memory management > related operations. Just curious: why? > + if ((old_addr & ~PMD_MASK) || (new_addr & ~PMD_MASK) > + || old_end - old_addr < PMD_SIZE)

Re: [PATCH v2 2/2] mm: speed up mremap by 500x on large regions

2018-10-15 Thread Martin Schwidefsky
On Mon, 15 Oct 2018 09:10:53 +0200 Christian Borntraeger wrote: > On 10/12/2018 03:37 AM, Joel Fernandes (Google) wrote: > > Android needs to mremap large regions of memory during memory management > > related operations. The mremap system call can be really slow if THP is > > not enabled. The bo

Re: [PATCH v2 2/2] mm: speed up mremap by 500x on large regions

2018-10-15 Thread Christian Borntraeger
On 10/12/2018 03:37 AM, Joel Fernandes (Google) wrote: > Android needs to mremap large regions of memory during memory management > related operations. The mremap system call can be really slow if THP is > not enabled. The bottleneck is move_page_tables, which is copying each > pte at a time, an