diff options
| author | Javier González <javier@cnexlabs.com> | 2017-10-13 14:46:45 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-10-13 16:34:57 +0200 |
| commit | 8da10cce7c7f7f9f5edc77271cf6e0c45b762004 (patch) | |
| tree | df5e06e0c677893b7376da4d6510e5538fe199c5 | |
| parent | lightnvm: pblk: cleanup unused and static functions (diff) | |
| download | linux-8da10cce7c7f7f9f5edc77271cf6e0c45b762004.tar.xz linux-8da10cce7c7f7f9f5edc77271cf6e0c45b762004.zip | |
lightnvm: pblk: avoid being reported as hung on rated GC
The amount of GC I/O on the write buffer is managed by the rate-limiter,
which is calculated as a function of the number of available free
blocks. When reaching the stable point, we risk having scheduled more
I/Os for GC than are allowed on the write buffer. This would result on
the GC semaphore balancing the outstanding read GC I/Os to be reported
as "hung", though the behavior is normal.
Solve this by allowing to schedule when we detect that the read GC path
is not moving forward.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/lightnvm/pblk-gc.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c index b8323e34d1bc..00d5698d64a9 100644 --- a/drivers/lightnvm/pblk-gc.c +++ b/drivers/lightnvm/pblk-gc.c @@ -218,7 +218,13 @@ next_rq: gc_rq_ws->line = line; gc_rq_ws->priv = gc_rq; - down(&gc->gc_sem); + /* The write GC path can be much slower than the read GC one due to + * the budget imposed by the rate-limiter. Balance in case that we get + * back pressure from the write GC path. + */ + while (down_timeout(&gc->gc_sem, msecs_to_jiffies(30000))) + io_schedule(); + kref_get(&line->ref); INIT_WORK(&gc_rq_ws->ws, pblk_gc_line_ws); |