On Tue, Jul 12, 2022 at 04:29:10PM +0200, Christoph Lameter wrote:
> On Tue, 12 Jul 2022, Hyeonggon Yoo wrote:
>
> > @@ -3241,31 +3219,46 @@ slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, size_t orig_
> > }
> >
> > static __always_inline void *
> > -__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
> > +__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags, int nodeid)
> > {
> > - void *objp;
> > + void *objp = NULL;
> > + int slab_node = numa_mem_id();
> >
> > - if (current->mempolicy || cpuset_do_slab_mem_spread()) {
> > - objp = alternate_node_alloc(cache, flags);
> > - if (objp)
> > - goto out;
> > + if (nodeid == NUMA_NO_NODE) {
> > + if (current->mempolicy || cpuset_do_slab_mem_spread()) {
> > + objp = alternate_node_alloc(cachep, flags);
> > + if (objp)
> > + goto out;
> > + }
> > + /*
> > + * Use the locally cached objects if possible.
> > + * However ____cache_alloc does not allow fallback
> > + * to other nodes. It may fail while we still have
> > + * objects on other nodes available.
> > + */
> > + objp = ____cache_alloc(cachep, flags);
> > + nodeid = slab_node;
> > + } else if (nodeid == slab_node) {
> > + objp = ____cache_alloc(cachep, flags);
> > + } else if (!get_node(cachep, nodeid)) {
> > + /* Node not bootstrapped yet */
> > + objp = fallback_alloc(cachep, flags);
> > + goto out;
> > }
> > - objp = ____cache_alloc(cache, flags);
> >
> > /*
> > * We may just have run out of memory on the local node.
> > * ____cache_alloc_node() knows how to locate memory on other nodes
> > */
> > if (!objp)
> > - objp = ____cache_alloc_node(cache, flags, numa_mem_id());
> > -
> > + objp = ____cache_alloc_node(cachep, flags, nodeid);
>
>
> Does this preserve the original behavior? nodeid is the parameter passed
> to __do_cache_alloc(). numa_mem_id() is the nearest memory node.
Yes it does preserve the original behavior.
nodeid equals to value of numa_mem_id() when nodeid was NUMA_NO_NODE and
____cache_alloc() failed to allocate.
