From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx> This patch attempts to minimize the delay in nfs root mount, which happens as side effect of nfs-root mount retry by changing the NFSROOT_TIMEOUT_MIN and NFSROOT_TIMEOUT_MAX values. Current strategy is, if do_mount_root fails, sleep for 5 seconds for the second attempt followed by a 5<<1 seconds delay for each loop with a maximum of 30 seconds delay. For 5 retries it would take. 5 + 10 + 20 + 30 + 30 = 95 Seconds with each do_mount_root timeout @ 3-4 seconds x 5 = 15 seconds. Which means Kernel can only attempt the succession root-mounts or panic after 110 seconds. So changing min and max timeouts will have the below delays. 0 + 1 + 3 + 7 + 15 = 26 Seconds. and with each do_mount_root timeout @ 3-4 seconds x 5 = 15 seconds. Which means Kernel can only attempt the succession root-mounts or panic after 41 seconds As, do_mount_root timesout in 3-4 seconds which should be sufficient delay to start of the second nfs mount attempt and increasing delay after that makes more sense. I clearly see an advantange in changing these values because, Without this patch my board mounts nfs in 9-10 seconds, however with this patch can mount nfs in 4-5 seconds. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx> --- Hello All, With latest kernel I can see that my nfs-root mounts with big delay of 5 seconds when compared to 2.6.32. It took 9-10 seconds, where as in 2.6.32 it took 4-5 seconds. However with modifications to NFSROOT_TIMEOUT_MIN and NFSROOT_TIMEOUT_MAX, nfs root mounts as it used to do it in 2.6.32. As first nfs mount timeout itself introduces sufficient delay to start the second retry. I think changing the min-max values will help people to nfs boot there boards faster than it is in 3.3 kernel. Comments ? Thanks. srini init/do_mounts.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/init/do_mounts.c b/init/do_mounts.c index ef6478f..b8214ce 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -361,8 +361,8 @@ out: #ifdef CONFIG_ROOT_NFS -#define NFSROOT_TIMEOUT_MIN 5 -#define NFSROOT_TIMEOUT_MAX 30 +#define NFSROOT_TIMEOUT_MIN 1 +#define NFSROOT_TIMEOUT_MAX 32 #define NFSROOT_RETRY_MAX 5 static int __init mount_nfs_root(void) @@ -390,7 +390,7 @@ static int __init mount_nfs_root(void) break; /* Wait, in case the server refused us immediately */ - ssleep(timeout); + ssleep(timeout - 1); timeout <<= 1; if (timeout > NFSROOT_TIMEOUT_MAX) timeout = NFSROOT_TIMEOUT_MAX; -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
