From: "xinhui.pan" <xinhuix.pan@intel.com>
To: linux-kernel@vger.kernel.org, agk@redhat.com, snitzer@redhat.com,
dm-devel@redhat.com
Cc: yanmin_zhang@linux.intel.com, "Liu, ShuoX" <shuox.liu@intel.com>
Subject: [PATCH] md/dm-ioctl.c: optimize memory allocation in copy_params
Date: Fri, 04 Jul 2014 18:22:32 +0800 [thread overview]
Message-ID: <53B68068.2060102@intel.com> (raw)
KMALLOC_MAX_SIZE is too big, it easily cause memory fragmented and low memory when param_kernel->data_size
is also big. That's not nice. So use vmalloc instead of kmalloc when size is larger than (PAGE_SIZE << 2).
There are other drivers using kmalloc to gain a big size memory. And that cause our devices to hit hang and
many worse issues. We don't benefit much when using kmalloc in such scenario.
Signed-off-by: xinhui.pan <xinhuiX.pan@intel.com>
Signed-off-by: yanmin.zhang <yanmin_zhang@linux.intel.com>
---
drivers/md/dm-ioctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 5152142..31c3af9 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1709,7 +1709,7 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern
* Use kmalloc() rather than vmalloc() when we can.
*/
dmi = NULL;
- if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
+ if (param_kernel->data_size <= (PAGE_SIZE << 2)) {
dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
if (dmi)
*param_flags |= DM_PARAMS_KMALLOC;
--
1.7.9.5
next reply other threads:[~2014-07-04 10:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-04 10:22 xinhui.pan [this message]
2014-07-08 22:39 ` [dm-devel] [PATCH] md/dm-ioctl.c: optimize memory allocation in copy_params Mikulas Patocka
2014-07-09 2:01 ` Zhang, Yanmin
2014-07-09 3:37 ` xinhui.pan
2014-07-09 14:53 ` Mikulas Patocka
2014-07-22 1:02 ` Zhang, Yanmin
2014-07-22 1:23 ` Alasdair G Kergon
2014-07-22 2:04 ` Alasdair G Kergon
2014-07-23 3:15 ` Zhang, Yanmin
2014-07-23 3:06 ` Zhang, Yanmin
2014-07-23 12:16 ` Mikulas Patocka
2014-07-23 12:54 ` Alasdair G Kergon
2014-07-23 17:14 ` Mikulas Patocka
2014-07-24 5:53 ` Zhang, Yanmin
2014-07-23 12:39 ` Mikulas Patocka
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