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mm/cma_debug: show complete cma name in debugfs directories

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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 <quic_charante@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavan Kondeti <quic_pkondeti@quicinc.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Charan Teja Kalla 2022-08-11 18:45:29 +05:30 committed by Andrew Morton
parent cf1e3fe497
commit 9a79443ddc
2 changed files with 6 additions and 9 deletions
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10
Documentation/admin-guide/mm/cma_debugfs.rst
View File

@ -5,10 +5,10 @@ CMA Debugfs Interface
The CMA debugfs interface is useful to retrieve basic information out of the 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. different CMA areas and to test allocation/release in each of the areas.
Each CMA zone represents a directory under <debugfs>/cma/, indexed by the Each CMA area represents a directory under <debugfs>/cma/, represented by
kernel's CMA index. So the first CMA zone would be: its CMA name like below:
<debugfs>/cma/cma-0 <debugfs>/cma/<cma_name>
The structure of the files created under that directory is as follows: 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. - [RO] bitmap: The bitmap of page states in the zone.
- [WO] alloc: Allocate N pages from that CMA area. For example:: - [WO] alloc: Allocate N pages from that CMA area. For example::
echo 5 > <debugfs>/cma/cma-2/alloc echo 5 > <debugfs>/cma/<cma_name>/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. - [WO] free: Free N pages from that CMA area, similar to the above.

5
mm/cma_debug.c
View File

@ -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) static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)
{ {
struct dentry *tmp; struct dentry *tmp;
char name[CMA_MAX_NAME];
scnprintf(name, sizeof(name), "cma-%s", cma->name); tmp = debugfs_create_dir(cma->name, root_dentry);
tmp = debugfs_create_dir(name, root_dentry);
debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops); debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops); debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);