From: Sasha Levin <sasha.levin@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: iamjoonsoo.kim@lge.com, m.szyprowski@samsung.com,
akpm@linux-foundation.org, lauraa@codeaurora.org,
Sasha Levin <sasha.levin@oracle.com>
Subject: [PATCH v3 3/3] mm: cma: release trigger
Date: Tue, 27 Jan 2015 21:22:57 -0500 [thread overview]
Message-ID: <1422411777-22332-4-git-send-email-sasha.levin@oracle.com> (raw)
In-Reply-To: <1422411777-22332-1-git-send-email-sasha.levin@oracle.com>
Provides a userspace interface to trigger a CMA release.
Usage:
echo [pages] > free
This would provide testing/fuzzing access to the CMA release paths.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
mm/cma_debug.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index 5bd6863..c29f029 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -39,6 +39,59 @@ 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 {
+ 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 +138,9 @@ 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,
--
1.7.10.4
next prev parent reply other threads:[~2015-01-28 2:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-28 2:22 [PATCH v3 0/3] mm: cma: debugfs access to CMA Sasha Levin
2015-01-28 2:22 ` [PATCH v3 1/3] mm: cma: debugfs interface Sasha Levin
2015-01-28 2:22 ` [PATCH v3 2/3] mm: cma: allocation trigger Sasha Levin
2015-01-28 2:22 ` Sasha Levin [this message]
2015-01-29 7:51 ` [PATCH v3 3/3] mm: cma: release trigger Joonsoo Kim
2015-01-29 13:04 ` Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1422411777-22332-4-git-send-email-sasha.levin@oracle.com \
--to=sasha.levin@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=iamjoonsoo.kim@lge.com \
--cc=lauraa@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).