mm: vmstat: add cma statistics

Since CMA is used more widely, it's worth to have CMA allocation
statistics into vmstat.  With it, we could know how agressively system
uses cma allocation and how often it fails.

Link: https://lkml.kernel.org/r/20210302183346.3707237-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: John Dias <joaodias@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 3 deletions

diff --git a/mm/cma.c b/mm/cma.c
index acd6991f77a0..b44a71eb3174 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -435,13 +435,13 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
 	int ret = -ENOMEM;
 
 	if (!cma || !cma->count || !cma->bitmap)
-		return NULL;
+		goto out;
 
 	pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
 		 count, align);
 
 	if (!count)
-		return NULL;
+		goto out;
 
 	mask = cma_bitmap_aligned_mask(cma, align);
 	offset = cma_bitmap_aligned_offset(cma, align);
@@ -449,7 +449,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
 	bitmap_count = cma_bitmap_pages_to_bits(cma, count);
 
 	if (bitmap_count > bitmap_maxno)
-		return NULL;
+		goto out;
 
 	for (;;) {
 		spin_lock_irq(&cma->lock);
@@ -506,6 +506,12 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
 	}
 
 	pr_debug("%s(): returned %p\n", __func__, page);
+out:
+	if (page)
+		count_vm_event(CMA_ALLOC_SUCCESS);
+	else
+		count_vm_event(CMA_ALLOC_FAIL);
+
 	return page;
 }