The CMA_ALLOC_SUCCESS, respectively CMA_ALLOC_FAIL, are increased by one after each cma_alloc() function call. This is done even though cma_alloc() can allocate an arbitrary number of CMA pages. When looking at /proc/vmstat, the number of successful (or failed) cma_alloc() calls doesn't tell much with regards to how many CMA pages were allocated via cma_alloc() versus via the page allocator (regular allocation request or PCP lists refill). This can also be rather confusing to a user who isn't familiar with the code, since the unit of measurement for nr_free_cma is the number of pages, but cma_alloc_success and cma_alloc_fail count the number of cma_alloc() function calls. Let's make this consistent, and arguably more useful, by having CMA_ALLOC_SUCCESS count the number of successfully allocated CMA pages, and CMA_ALLOC_FAIL count the number of pages the cma_alloc() failed to allocate. For users that wish to track the number of cma_alloc() calls, there are tracepoints for that already implemented. Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> --- mm/cma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index f49c95f8ee37..dbf7fe8cb1bd 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -517,10 +517,10 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, pr_debug("%s(): returned %p\n", __func__, page); out: if (page) { - count_vm_event(CMA_ALLOC_SUCCESS); + count_vm_events(CMA_ALLOC_SUCCESS, count); cma_sysfs_account_success_pages(cma, count); } else { - count_vm_event(CMA_ALLOC_FAIL); + count_vm_events(CMA_ALLOC_FAIL, count); if (cma) cma_sysfs_account_fail_pages(cma, count); } -- 2.43.0