On Wed, 2018-10-31 at 15:40 +0000, Pasha Tatashin wrote: > > On 10/17/18 7:54 PM, Alexander Duyck wrote: > > This patch introduces a new iterator for_each_free_mem_pfn_range_in_zone. > > > > This iterator will take care of making sure a given memory range provided > > is in fact contained within a zone. It takes are of all the bounds checking > > we were doing in deferred_grow_zone, and deferred_init_memmap. In addition > > it should help to speed up the search a bit by iterating until the end of a > > range is greater than the start of the zone pfn range, and will exit > > completely if the start is beyond the end of the zone. > > > > This patch adds yet another iterator called > > for_each_free_mem_range_in_zone_from and then uses it to support > > initializing and freeing pages in groups no larger than MAX_ORDER_NR_PAGES. > > By doing this we can greatly improve the cache locality of the pages while > > we do several loops over them in the init and freeing process. > > > > We are able to tighten the loops as a result since we only really need the > > checks for first_init_pfn in our first iteration and after that we can > > assume that all future values will be greater than this. So I have added a > > function called deferred_init_mem_pfn_range_in_zone that primes the > > iterators and if it fails we can just exit. > > > > On my x86_64 test system with 384GB of memory per node I saw a reduction in > > initialization time from 1.85s to 1.38s as a result of this patch. > > > > Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> > > Hi Alex, > > Could you please split this patch into two parts: > > 1. Add deferred_init_maxorder() > 2. Add memblock iterator? > > This would allow a better bisecting in case of problems. Chaning two > loops into deferred_init_maxorder() while a good idea, is still > non-trivial and might lead to bugs. > > Thank you, > Pavel I can do that, but I will need to flip the order. I will add the new iterator first and then deferred_init_maxorder. Otherwise the intermediate step ends up being too much throw-away code. - Alex
