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dma-debug: Expose nr_total_entries in debugfs 

Expose nr_total_entries in debugfs, so that {num,min}_free_entries
become even more meaningful to users interested in current/maximum
utilisation. This becomes even more relevant once nr_total_entries
may change at runtime beyond just the existing AMD GART debug code.

Suggested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Christoph Hellwig <hch@lst.de>
hifive-unleashed-5.1
Robin Murphy 2018-12-10 14:00:28 +00:00 committed by Christoph Hellwig
parent 7c703e54cc
commit 9f191555ba
2 changed files with 10 additions and 0 deletions
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3
Documentation/DMA-API.txt
View File

@ -723,6 +723,9 @@ dma-api/min_free_entries This read-only file can be read to get the
dma-api/num_free_entries The current number of free dma_debug_entries
in the allocator.
dma-api/nr_total_entries The total number of dma_debug_entries in the
allocator, both free and used.
dma-api/driver-filter You can write a name of a driver into this file
to limit the debug output to requests from that
particular driver. Write an empty string to

7
kernel/dma/debug.c
View File

@ -142,6 +142,7 @@ static struct dentry *show_all_errors_dent __read_mostly;
static struct dentry *show_num_errors_dent __read_mostly;
static struct dentry *num_free_entries_dent __read_mostly;
static struct dentry *min_free_entries_dent __read_mostly;
static struct dentry *nr_total_entries_dent __read_mostly;
static struct dentry *filter_dent __read_mostly;
/* per-driver filter related state */
@ -926,6 +927,12 @@ static int dma_debug_fs_init(void)
if (!min_free_entries_dent)
goto out_err;
nr_total_entries_dent = debugfs_create_u32("nr_total_entries", 0444,
dma_debug_dent,
&nr_total_entries);
if (!nr_total_entries_dent)
goto out_err;
filter_dent = debugfs_create_file("driver_filter", 0644,
dma_debug_dent, NULL, &filter_fops);
if (!filter_dent)