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author | Sasha Levin <sasha.levin@oracle.com> | 2015-04-14 15:45:02 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 16:49:00 -0700 |
commit | 8325330b026509127d4541e0f511c0c10648c2d5 (patch) | |
tree | 1db659fbd241f7810c44cfd4e1db22887a04fb73 /mm/cma_debug.c | |
parent | 26b02a1f9670862c51b3ff63a6128589866f5c71 (diff) | |
download | blackbird-op-linux-8325330b026509127d4541e0f511c0c10648c2d5.tar.gz blackbird-op-linux-8325330b026509127d4541e0f511c0c10648c2d5.zip |
mm: cma: release trigger
Provides a userspace interface to trigger a CMA release.
Usage:
echo [pages] > free
This would provide testing/fuzzing access to the CMA release paths.
[akpm@linux-foundation.org: coding-style fixes]
[mhocko@suse.cz: fix build]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/cma_debug.c')
-rw-r--r-- | mm/cma_debug.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/mm/cma_debug.c b/mm/cma_debug.c index f3baa413ab33..ae41faeed596 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -10,6 +10,7 @@ #include <linux/list.h> #include <linux/kernel.h> #include <linux/slab.h> +#include <linux/mm_types.h> #include "cma.h" @@ -39,6 +40,60 @@ static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem) spin_unlock(&cma->mem_head_lock); } +static struct cma_mem *cma_get_entry_from_list(struct cma *cma) +{ + struct cma_mem *mem = NULL; + + spin_lock(&cma->mem_head_lock); + if (!hlist_empty(&cma->mem_head)) { + mem = hlist_entry(cma->mem_head.first, struct cma_mem, node); + hlist_del_init(&mem->node); + } + spin_unlock(&cma->mem_head_lock); + + return mem; +} + +static int cma_free_mem(struct cma *cma, int count) +{ + struct cma_mem *mem = NULL; + + while (count) { + mem = cma_get_entry_from_list(cma); + if (mem == NULL) + return 0; + + if (mem->n <= count) { + cma_release(cma, mem->p, mem->n); + count -= mem->n; + kfree(mem); + } else if (cma->order_per_bit == 0) { + cma_release(cma, mem->p, count); + mem->p += count; + mem->n -= count; + count = 0; + cma_add_to_cma_mem_list(cma, mem); + } else { + pr_debug("cma: cannot release partial block when order_per_bit != 0\n"); + cma_add_to_cma_mem_list(cma, mem); + break; + } + } + + return 0; + +} + +static int cma_free_write(void *data, u64 val) +{ + int pages = val; + struct cma *cma = data; + + return cma_free_mem(cma, pages); +} + +DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n"); + static int cma_alloc_mem(struct cma *cma, int count) { struct cma_mem *mem; @@ -85,6 +140,9 @@ static void cma_debugfs_add_one(struct cma *cma, int idx) debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma, &cma_alloc_fops); + debugfs_create_file("free", S_IWUSR, cma_debugfs_root, cma, + &cma_free_fops); + debugfs_create_file("base_pfn", S_IRUGO, tmp, &cma->base_pfn, &cma_debugfs_fops); debugfs_create_file("count", S_IRUGO, tmp, |