From 43ca106fa8ec7d684776fbe561214d3b2b7cb9cb Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Tue, 4 May 2021 18:37:28 -0700 Subject: mm: cma: support sysfs Since CMA is getting used more widely, it's more important to keep monitoring CMA statistics for system health since it's directly related to user experience. This patch introduces sysfs statistics for CMA, in order to provide some basic monitoring of the CMA allocator. * the number of CMA page successful allocations * the number of CMA page allocation failures These two values allow the user to calcuate the allocation failure rate for each CMA area. e.g.) /sys/kernel/mm/cma/WIFI/alloc_pages_[success|fail] /sys/kernel/mm/cma/SENSOR/alloc_pages_[success|fail] /sys/kernel/mm/cma/BLUETOOTH/alloc_pages_[success|fail] The cma_stat was intentionally allocated by dynamic allocation to harmonize with kobject lifetime management. https://lore.kernel.org/linux-mm/YCOAmXqt6dZkCQYs@kroah.com/ Link: https://lkml.kernel.org/r/20210324230759.2213957-1-minchan@kernel.org Link: https://lore.kernel.org/linux-mm/20210316100433.17665-1-colin.king@canonical.com/ Signed-off-by: Minchan Kim Signed-off-by: Colin Ian King Tested-by: Dmitry Osipenko Reviewed-by: Dmitry Osipenko Reviewed-by: Greg Kroah-Hartman Reviewed-by: John Hubbard Tested-by: Anders Roxell Cc: Suren Baghdasaryan Cc: John Dias Cc: Matthew Wilcox (Oracle) Cc: Colin Ian King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/cma.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'mm/cma.c') diff --git a/mm/cma.c b/mm/cma.c index d1a4c06b5039..2380f2571eb5 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -511,10 +511,14 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, pr_debug("%s(): returned %p\n", __func__, page); out: - if (page) + if (page) { count_vm_event(CMA_ALLOC_SUCCESS); - else + cma_sysfs_account_success_pages(cma, count); + } else { count_vm_event(CMA_ALLOC_FAIL); + if (cma) + cma_sysfs_account_fail_pages(cma, count); + } return page; } -- cgit v1.2.3-58-ga151