From 9a79443ddc3b9c3e1c4766209b86770585b5f7cc Mon Sep 17 00:00:00 2001 From: Charan Teja Kalla Date: Thu, 11 Aug 2022 18:45:29 +0530 Subject: [PATCH] mm/cma_debug: show complete cma name in debugfs directories Currently only 12 characters of the cma name is being used as the debug directories where as the cma name can be of length CMA_MAX_NAME(=64) characters. One side problem with this is having 2 cma's with first common 12 characters would end up in trying to create directories with same name and fails with -EEXIST thus can limit cma debug functionality. The 'cma-' prefix is used initially where cma areas don't have any names and are represented by simple integer values. Since now each cma would be having its own name, drop 'cma-' prefix for the cma debug directories as they are clearly evident that they are for cma debug through creating them in /sys/kernel/debug/cma/ path. Link: https://lkml.kernel.org/r/1660223729-22461-1-git-send-email-quic_charante@quicinc.com Signed-off-by: Charan Teja Kalla Cc: David Hildenbrand Cc: Vlastimil Babka Cc: Pavan Kondeti Cc: Minchan Kim Signed-off-by: Andrew Morton --- Documentation/admin-guide/mm/cma_debugfs.rst | 10 +++++----- mm/cma_debug.c | 5 +---- 2 files changed, 6 insertions(+), 9 deletions(-) diff --git a/Documentation/admin-guide/mm/cma_debugfs.rst b/Documentation/admin-guide/mm/cma_debugfs.rst index 4e06ffabd78a..7367e6294ef6 100644 --- a/Documentation/admin-guide/mm/cma_debugfs.rst +++ b/Documentation/admin-guide/mm/cma_debugfs.rst @@ -5,10 +5,10 @@ CMA Debugfs Interface The CMA debugfs interface is useful to retrieve basic information out of the different CMA areas and to test allocation/release in each of the areas. -Each CMA zone represents a directory under /cma/, indexed by the -kernel's CMA index. So the first CMA zone would be: +Each CMA area represents a directory under /cma/, represented by +its CMA name like below: - /cma/cma-0 + /cma/ The structure of the files created under that directory is as follows: @@ -18,8 +18,8 @@ The structure of the files created under that directory is as follows: - [RO] bitmap: The bitmap of page states in the zone. - [WO] alloc: Allocate N pages from that CMA area. For example:: - echo 5 > /cma/cma-2/alloc + echo 5 > /cma//alloc -would try to allocate 5 pages from the cma-2 area. +would try to allocate 5 pages from the 'cma_name' area. - [WO] free: Free N pages from that CMA area, similar to the above. diff --git a/mm/cma_debug.c b/mm/cma_debug.c index c3ffe253e055..602fff89b15f 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -163,11 +163,8 @@ DEFINE_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n"); static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry) { struct dentry *tmp; - char name[CMA_MAX_NAME]; - scnprintf(name, sizeof(name), "cma-%s", cma->name); - - tmp = debugfs_create_dir(name, root_dentry); + tmp = debugfs_create_dir(cma->name, root_dentry); debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops); debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);