Re: [PATCH] mm: fix panic in __alloc_pages
From: Alexey Makhalov <hidden>
Date: 2021-11-08 06:12:20
Also in:
lkml, stable
I’m going to send patch v2, with node_online check moved to caller (pcpu_alloc_pages() function) as was suggested by David. It seems as it is only one place which passes present but offlined node to alloc-pages_node(). Moving node online check to the caller keeps hot path (alloc_pages) simple and performant.
quoted hunk ↗ jump to hunk
diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c index 2054c9213c43..c21ff5bb91dc 100644 --- a/mm/percpu-vm.c +++ b/mm/percpu-vm.c@@ -84,15 +84,19 @@ static int pcpu_alloc_pages(struct pcpu_chunk *chunk, gfp_t gfp){ unsigned int cpu, tcpu; - int i; + int i, nid; gfp |= __GFP_HIGHMEM; for_each_possible_cpu(cpu) { + nid = cpu_to_node(cpu); + + if (nid == NUMA_NO_NODE || !node_online(nid)) + nid = numa_mem_id(); for (i = page_start; i < page_end; i++) { struct page **pagep = &pages[pcpu_page_idx(cpu, i)]; - *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0); + *pagep = alloc_pages_node(nid, gfp, 0); if (!*pagep) goto err; }
Thanks, —Alexey
Attachments
- signature.asc [application/pgp-signature] 833 bytes