Dear Colin, thanks for reply. In our system, most buffers are cached. We found that calling alloc_pages with __GFP_ZERO flag is very slow. But if using page pool, we zero pages in defer free, allocation from page pool will be very fast. This gives a large performance gain. Is there any potential risk if we use page pool on cache buffer? Thanks very much !
2014-03-28 4:59 GMT+08:00 Colin Cross <[email protected]>: > On Thu, Mar 27, 2014 at 7:54 AM, kai zhang <[email protected]> > wrote: > > Dears > > In ion system heap, when buffer->flags has ION_FLAG_CACHED, the > > allocation uses alloc_pages instead of using page pool. > > Why can't cached buffer allocate from page pool? > > thanks very much! > > The page pool is designed as an optimization to avoid having to cache > flush pages to turn them into uncached pages. Using the page pools > for cached pages should be unnecessary - the kernel mm subsystem's > freelists should act similarly to the page pools. > -- -- unsubscribe: [email protected] website: http://groups.google.com/group/android-kernel --- You received this message because you are subscribed to the Google Groups "Android Linux Kernel Development" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
