Re: [dm-devel] Re: 2.6.24 Kernel Soft Lock Up with heavy I/O in dm-crypt

[Milan Broz <mbroz@redhat.com>]

Ritesh Raj Sarraf wrote:

> 1) Initialize a device using dm-crypt and LUKS
> 2) Create a filesystem on top of it and mount it.
> 3) Write huge amount of data (as a normal user). Something like 150GB.
>
> As the load goes hight (to something like 12-14), the kernel lock-up is logged 
> into dmesg.
> At that moment, the OS is barely responsive.
>
>   
Please could you try to reproduce it with this patch applied?
(patch for 2.6.25-rc3, for 2.6.24 will follow - code changed here)

Milan
mbroz@redhat.com
--

Add cond_resched() to prevent stuck in big bio processing.

Signed-off-by: Milan Broz <mbroz@redhat.com>
---
 drivers/md/dm-crypt.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index b04f98d..2032228 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -432,6 +432,7 @@ static int crypt_convert(struct crypt_config *cc,
 			/* fall through*/
 		case 0:
 			ctx->sector++;
+			cond_resched();
 			continue;
 		}