On Mon, Mar 22, 2021 at 07:38:20PM +0000, Matthew Wilcox (Oracle) wrote: > If we're trying to allocate 4MB of memory, the table will be 8KiB in size > (1024 pointers * 8 bytes per pointer), which can usually be satisfied > by a kmalloc (which is significantly faster). Instead of changing this > open-coded implementation, just use kvmalloc(). > > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > --- > mm/vmalloc.c | 7 +------ > 1 file changed, 1 insertion(+), 6 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 96444d64129a..32b640a84250 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2802,13 +2802,8 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > gfp_mask |= __GFP_HIGHMEM; > > /* Please note that the recursion is strictly bounded. */ > - if (array_size > PAGE_SIZE) { > - pages = __vmalloc_node(array_size, 1, nested_gfp, node, > + pages = kvmalloc_node_caller(array_size, nested_gfp, node, > area->caller); > - } else { > - pages = kmalloc_node(array_size, nested_gfp, node); > - } > - > if (!pages) { > free_vm_area(area); > return NULL; > -- > 2.30.2 Makes sense to me. Though i expected a bigger difference: # patch single CPU, 4MB allocation, loops: 1000000 avg: 85293854 usec # default single CPU, 4MB allocation, loops: 1000000 avg: 89275857 usec One question. Should we care much about fragmentation? I mean with the patch, allocations > 2MB will do request to SLAB bigger then PAGE_SIZE. Thanks! -- Vlad Rezki