diff options
| author | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2021-09-02 14:57:16 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-03 09:58:14 -0700 |
| commit | 343ab8178f318b6006d54865972ff9c433b29e10 (patch) | |
| tree | 79777182053073e5c580bfc5293da7f22a32e49f /mm/vmalloc.c | |
| parent | bdbda735508ca83341899a77f143e4d5c58007b3 (diff) | |
mm/vmalloc: use batched page requests in bulk-allocator
In case of simultaneous vmalloc allocations, for example it is 1GB and 12
CPUs my system is able to hit "BUG: soft lockup" for !CONFIG_PREEMPT
kernel.
RIP: 0010:__alloc_pages_bulk+0xa9f/0xbb0
Call Trace:
__vmalloc_node_range+0x11c/0x2d0
__vmalloc_node+0x4b/0x70
fix_size_alloc_test+0x44/0x60 [test_vmalloc]
test_func+0xe7/0x1f0 [test_vmalloc]
kthread+0x11a/0x140
ret_from_fork+0x22/0x30
To address this issue invoke a bulk-allocator many times until all pages
are obtained, i.e. do batched page requests adding cond_resched()
meanwhile to reschedule. Batched value is hard-coded and is 100 pages per
call.
Link: https://lkml.kernel.org/r/20210707182639.31282-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nicholas Piggin <npiggin@gmail.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>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d5cd52805149..24bc65f02d04 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2779,7 +2779,7 @@ EXPORT_SYMBOL_GPL(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 order, unsigned int nr_pages, struct page **pages) { unsigned int nr_allocated = 0; @@ -2789,10 +2789,32 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * 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 + if (!order) { + while (nr_allocated < nr_pages) { + unsigned int nr, nr_pages_request; + + /* + * A maximum allowed request is hard-coded and is 100 + * pages per call. That is done in order to prevent a + * long preemption off scenario in the bulk-allocator + * so the range is [1:100]. + */ + nr_pages_request = min(100U, nr_pages - nr_allocated); + + nr = alloc_pages_bulk_array_node(gfp, nid, + nr_pages_request, pages + nr_allocated); + + nr_allocated += nr; + cond_resched(); + + /* + * If zero or pages were obtained partly, + * fallback to a single page allocator. + */ + if (nr != nr_pages_request) + break; + } + } else /* * Compound pages required for remap_vmalloc_page if * high-order pages. |