Message ID | 20210324150518.2734402-4-willy@infradead.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | vmalloc: Improve vmalloc(4MB) performance | expand |
On Wed, 24 Mar 2021, 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(). > > This improves the allocation speed of vmalloc(4MB) by approximately > 5% in our benchmark. It's still dominated by the 1024 calls to > alloc_pages_node(), which will be the subject of a later patch. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Rientjes <rientjes@google.com>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a22241e9c363..a9ed2a4b697e 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2801,13 +2801,8 @@ 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;
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(). This improves the allocation speed of vmalloc(4MB) by approximately 5% in our benchmark. It's still dominated by the 1024 calls to alloc_pages_node(), which will be the subject of a later patch. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/vmalloc.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-)