BACKPORT: Fix merge Revert "mm/cma.c: remove redundant cma_mutex lock"

scpcom · scpcom · commit d596e6a5d260 · 2022-12-30T16:24:46.000+01:00
diff --git a/mm/cma.c b/mm/cma.c
@@ -535,6 +535,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
 			lru_cache_enable();
 			goto out;
 		}
+		mutex_lock(&cma_mutex);
 		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp_mask, &info);
 		mutex_unlock(&cma_mutex);
 		cma_info.nr_migrated += info.nr_migrated;

Original file line number	Diff line number	Diff line change
`@@ -535,6 +535,7 @@ struct page cma_alloc(struct cma cma, size_t count, unsigned int align,`
`535`	`535`	`lru_cache_enable();`
`536`	`536`	`goto out;`
`537`	`537`	`}`
	`538`	`+ mutex_lock(&cma_mutex);`
`538`	`539`	`ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp_mask, &info);`
`539`	`540`	`mutex_unlock(&cma_mutex);`
`540`	`541`	`cma_info.nr_migrated += info.nr_migrated;`