On Thu 30-03-17 16:21:43, Shakeel Butt wrote: > On Mon, Mar 6, 2017 at 2:33 AM, Michal Hocko <[email protected]> wrote: > > From: Michal Hocko <[email protected]> > > > > fq_alloc_node, alloc_netdev_mqs and netif_alloc* open code kmalloc > > with vmalloc fallback. Use the kvmalloc variant instead. Keep the > > __GFP_REPEAT flag based on explanation from Eric: > > " > > At the time, tests on the hardware I had in my labs showed that > > vmalloc() could deliver pages spread all over the memory and that was a > > small penalty (once memory is fragmented enough, not at boot time) > > " > > > > The way how the code is constructed means, however, that we prefer to go > > and hit the OOM killer before we fall back to the vmalloc for requests > > <=32kB (with 4kB pages) in the current code. This is rather disruptive for > > something that can be achived with the fallback. On the other hand > > __GFP_REPEAT doesn't have any useful semantic for these requests. So the > > effect of this patch is that requests smaller than 64kB will fallback to > > I am a bit confused about this 64kB, shouldn't it be <=32kB (with 4kB > pages & PAGE_ALLOC_COSTLY_ORDER = 3)?
You are right. I just forgot to update wording. "mm: support __GFP_REPEAT in kvmalloc_node for >32kB" was fixed but this one stayed in place. s@smaller than 64kB@which fit into 32kB@ Andrew could you update the changelog please? -- Michal Hocko SUSE Labs
