From b8cb86fd95bb461c3496e1f4b4083b198c963a9c Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 10 Nov 2016 16:21:20 +0100 Subject: [PATCH] staging: lustre: ldlm: pl_recalc time handling is wrong 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@vger.kernel.org # v4.4+ Fixes: 8f83409cf238 ("staging/lustre: use 64-bit time for pl_recalc") Reported-by: James Simmons Signed-off-by: Arnd Bergmann Reviewed-by: James Simmons Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lustre/ldlm/ldlm_pool.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) 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); -- 2.20.1