On Mon, Oct 09, 2023 at 05:14:15PM -0700, Andrew Morton wrote: > On Sun, 8 Oct 2023 15:54:40 +0800 Zhaoyang Huang <huangzhaoyang@xxxxxxxxx> wrote: > > > > Roman previously asked > > > > > > : Also I'm a bit concerned about potential performance implications. > > > : Would be great to provide some benchmarks or some data. Probably it's > > > : ok because of we have pcp caches on top, but I'm not 100% sure. > > > > > > Are you able to perform such testing and tell us the result? > > I have applied this patch in a v5.4 based ANDROID system and got no > > regression problem. Actually, this commit is aimed to have > > alloc_pages(GFP_USER) use CMA instead of stealing U&R(could lead to > > GFP_KERNEL fail) only when zone's free pages and free cma are around > > WATERMARK_LOW/MIN which would NOT affect most scenarios. > > OK, thanks. > > Could the appropriate people please take a look at this? It has been > in mm-unstable since May. I have 2 concerns: 1) it's still hard to understand the commit message and comments, I can only reverse-engineer it based on the code changes; 2) performance concerns I expressed earlier are not addressed. Idk what's a good benchmark for the page allocator, probably something i/o or networking heavy. On the positive side I believe that the patch is solving a real problem.
