James Simmons reports:
> The ldlm_pool field pl_recalc_time is set to the current
> monotonic clock value but the interval period is calculated
> with the wall clock. This means the interval period will
> always be far larger than the pl_recalc_period, which is
> just a small interval time period. The correct thing to
> do is to use monotomic clock current value instead of the
> wall clocks value when calculating recalc_interval_sec.
This broke when I converted the 32-bit get_seconds() into
ktime_get_{real_,}seconds() inconsistently. Either
one of those two would have worked, but mixing them
does not.
Staying with the original intention of the patch, this
changes the ktime_get_seconds() calls into ktime_get_real_seconds(),
using real time instead of mononic time.
Cc: stable@xxxxxxxxxxxxxxx # v4.4+
Fixes: 8f83409cf238 ("staging/lustre: use 64-bit time for pl_recalc")
Reported-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
v2: James' patch was similarly incomplete to mine, as it only
addressed some of the calls. With this new version, all ktime
accessors use the same time domain.
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c b/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
index 19831c555c49..b820309d70e3 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
@@ -356,10 +356,10 @@ static int ldlm_pool_recalc(struct ldlm_pool *pl)
u32 recalc_interval_sec;
int count;
- recalc_interval_sec = ktime_get_seconds() - pl->pl_recalc_time;
+ recalc_interval_sec = ktime_get_real_seconds() - pl->pl_recalc_time;
if (recalc_interval_sec > 0) {
spin_lock(&pl->pl_lock);
- recalc_interval_sec = ktime_get_seconds() - pl->pl_recalc_time;
+ recalc_interval_sec = ktime_get_real_seconds() - pl->pl_recalc_time;
if (recalc_interval_sec > 0) {
/*
@@ -382,7 +382,7 @@ static int ldlm_pool_recalc(struct ldlm_pool *pl)
count);
}
- recalc_interval_sec = pl->pl_recalc_time - ktime_get_seconds() +
+ recalc_interval_sec = pl->pl_recalc_time - ktime_get_real_seconds() +
pl->pl_recalc_period;
if (recalc_interval_sec <= 0) {
/* DEBUG: should be re-removed after LU-4536 is fixed */
@@ -657,7 +657,7 @@ int ldlm_pool_init(struct ldlm_pool *pl, struct ldlm_namespace *ns,
spin_lock_init(&pl->pl_lock);
atomic_set(&pl->pl_granted, 0);
- pl->pl_recalc_time = ktime_get_seconds();
+ pl->pl_recalc_time = ktime_get_real_seconds();
atomic_set(&pl->pl_lock_volume_factor, 1);
atomic_set(&pl->pl_grant_rate, 0);
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