On Fri, 2016-05-20 at 15:36 +0200, peter enderborg wrote: > From: Peter Enderborg <peter.enderb...@sonymobile.com> > > When sending data the socket allocates memory for > payload on a cache or a page alloc. The page alloc > then might trigger compation that takes long time. > This can be avoided with smaller chunks. But > userspace can not know what is the right size for > the smaller sends. For this we add a SIZEHINT > getsocketopt where the userspace can get the size > for send that will fit into one page (order 0) or > the max for a slab cache allocation.
Very obscure thing if you ask me. Exposing kernel internals like that seems to work around a more serious issue. What kind of sockets would ever use KMALLOC_MAX_CACHE_SIZE allocations exactly ? af_unix and tcp are definitely clean. 28d6427109d13b0f447cba5761f88d3548e83605 net: attempt high order allocations in sock_alloc_send_pskb() e370a7236321773245c5522d8bb299380830d3b2 af_unix: improve STREAM behavior with fragmented memory eb6a24816b247c0be6b2e97e68933072874bbe54 af_unix: reduce high order page allocations
