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mm/vmalloc: fallback to a single page allocator 

Currently for order-0 pages we use a bulk-page allocator to get set of
pages.  From the other hand not allocating all pages is something that
might occur.  In that case we should fallbak to the single-page allocator
trying to get missing pages, because it is more permissive(direct reclaim,
etc).

Introduce a vm_area_alloc_pages() function where the described logic is
implemented.

Link: https://lkml.kernel.org/r/20210521130718.GA17882@pc638.lan
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Uladzislau Rezki 2021-06-28 19:40:23 -07:00 committed by Linus Torvalds
parent f4bdfeaf18
commit 12b9f873a5
1 changed files with 52 additions and 29 deletions
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81
mm/vmalloc.c
View File

@ -2758,6 +2758,54 @@ void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
EXPORT_SYMBOL_GPL(vmap_pfn);
#endif /* CONFIG_VMAP_PFN */
static inline unsigned int
vm_area_alloc_pages(gfp_t gfp, int nid,
unsigned int order, unsigned long nr_pages, struct page **pages)
{
unsigned int nr_allocated = 0;
/*
* For order-0 pages we make use of bulk allocator, if
* the page array is partly or not at all populated due
* to fails, fallback to a single page allocator that is
* more permissive.
*/
if (!order)
nr_allocated = alloc_pages_bulk_array_node(
gfp, nid, nr_pages, pages);
else
/*
* Compound pages required for remap_vmalloc_page if
* high-order pages.
*/
gfp |= __GFP_COMP;
/* High-order pages or fallback path if "bulk" fails. */
while (nr_allocated < nr_pages) {
struct page *page;
int i;
page = alloc_pages_node(nid, gfp, order);
if (unlikely(!page))
break;
/*
* Careful, we allocate and map page-order pages, but
* tracking is done per PAGE_SIZE page so as to keep the
* vm_struct APIs independent of the physical/mapped size.
*/
for (i = 0; i < (1U << order); i++)
pages[nr_allocated + i] = page + i;
if (gfpflags_allow_blocking(gfp))
cond_resched();
nr_allocated += 1U << order;
}
return nr_allocated;
}
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
pgprot_t prot, unsigned int page_shift,
int node)
@ -2790,37 +2838,11 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
return NULL;
}
area->nr_pages = 0;
set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
page_order = vm_area_page_order(area);
if (!page_order) {
area->nr_pages = alloc_pages_bulk_array_node(
gfp_mask, node, nr_small_pages, area->pages);
} else {
/*
* Careful, we allocate and map page_order pages, but tracking is done
* per PAGE_SIZE page so as to keep the vm_struct APIs independent of
* the physical/mapped size.
*/
while (area->nr_pages < nr_small_pages) {
struct page *page;
int i;
/* Compound pages required for remap_vmalloc_page */
page = alloc_pages_node(node, gfp_mask | __GFP_COMP, page_order);
if (unlikely(!page))
break;
for (i = 0; i < (1U << page_order); i++)
area->pages[area->nr_pages + i] = page + i;
if (gfpflags_allow_blocking(gfp_mask))
cond_resched();
area->nr_pages += 1U << page_order;
}
}
area->nr_pages = vm_area_alloc_pages(gfp_mask, node,
page_order, nr_small_pages, area->pages);
atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
@ -2835,7 +2857,8 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
goto fail;
}
if (vmap_pages_range(addr, addr + size, prot, area->pages, page_shift) < 0) {
if (vmap_pages_range(addr, addr + size, prot, area->pages,
page_shift) < 0) {
warn_alloc(gfp_mask, NULL,
"vmalloc error: size %lu, failed to map pages",
area->nr_pages * PAGE_SIZE);