projects / people / pmueller / ipfire-2.x.git / blame
| Commit | Line | Data |
|---|---|---|
| 2cb7cef9 BS |
1 | From eea1bf384e05b5ab747f8530c4fba9e9e6907fff Mon Sep 17 00:00:00 2001 |
| 2 | From: NeilBrown <neilb@suse.de> | |
| 3 | Date: Tue, 31 Mar 2009 14:27:02 +1100 | |
| 4 | Subject: [PATCH] md: Fix is_mddev_idle test (again). | |
| 5 | ||
| 6 | There are two problems with is_mddev_idle. | |
| 7 | ||
| 8 | 1/ sync_io is 'atomic_t' and hence 'int'. curr_events and all the | |
| 9 | rest are 'long'. | |
| 10 | So if sync_io were to wrap on a 64bit host, the value of | |
| 11 | curr_events would go very negative suddenly, and take a very | |
| 12 | long time to return to positive. | |
| 13 | ||
| 14 | So do all calculations as 'int'. That gives us plenty of precision | |
| 15 | for what we need. | |
| 16 | ||
| 17 | 2/ To initialise rdev->last_events we simply call is_mddev_idle, on | |
| 18 | the assumption that it will make sure that last_events is in a | |
| 19 | suitable range. It used to do this, but now it does not. | |
| 20 | So now we need to be more explicit about initialisation. | |
| 21 | ||
| 22 | NOTE: to avoid kabi issues in SLES11, we leave 'last_events' as | |
| 23 | long and cast it to (int) where used. | |
| 24 | ||
| 25 | Signed-off-by: NeilBrown <neilb@suse.de> | |
| 26 | --- | |
| 27 | drivers/md/md.c | 10 +++++----- | |
| 28 | 1 file changed, 5 insertions(+), 5 deletions(-) | |
| 29 | ||
| 30 | --- linux-2.6.27-SLE11_BRANCH.orig/drivers/md/md.c | |
| 31 | +++ linux-2.6.27-SLE11_BRANCH/drivers/md/md.c | |
| 32 | @@ -5582,11 +5582,11 @@ int unregister_md_personality(struct mdk | |
| 33 | return 0; | |
| 34 | } | |
| 35 | ||
| 36 | -static int is_mddev_idle(mddev_t *mddev) | |
| 37 | +static int is_mddev_idle(mddev_t *mddev, int init) | |
| 38 | { | |
| 39 | mdk_rdev_t * rdev; | |
| 40 | int idle; | |
| 41 | - long curr_events; | |
| 42 | + int curr_events; | |
| 43 | ||
| 44 | idle = 1; | |
| 45 | rcu_read_lock(); | |
| 46 | @@ -5617,7 +5617,7 @@ static int is_mddev_idle(mddev_t *mddev) | |
| 47 | * always make curr_events less than last_events. | |
| 48 | * | |
| 49 | */ | |
| 50 | - if (curr_events - rdev->last_events > 4096) { | |
| 51 | + if (init || curr_events - (int)rdev->last_events > 64) { | |
| 52 | rdev->last_events = curr_events; | |
| 53 | idle = 0; | |
| 54 | } | |
| 55 | @@ -5861,7 +5861,7 @@ void md_do_sync(mddev_t *mddev) | |
| 56 | "(but not more than %d KB/sec) for %s.\n", | |
| 57 | speed_max(mddev), desc); | |
| 58 | ||
| 59 | - is_mddev_idle(mddev); /* this also initializes IO event counters */ | |
| 60 | + is_mddev_idle(mddev, 1); /* this initializes IO event counters */ | |
| 61 | ||
| 62 | io_sectors = 0; | |
| 63 | for (m = 0; m < SYNC_MARKS; m++) { | |
| 64 | @@ -5963,7 +5963,7 @@ void md_do_sync(mddev_t *mddev) | |
| 65 | ||
| 66 | if (currspeed > speed_min(mddev)) { | |
| 67 | if ((currspeed > speed_max(mddev)) || | |
| 68 | - !is_mddev_idle(mddev)) { | |
| 69 | + !is_mddev_idle(mddev, 0)) { | |
| 70 | msleep(500); | |
| 71 | goto repeat; | |
| 72 | } |