diff options
| author | NeilBrown <neilb@suse.de> | 2023-07-31 16:48:28 +1000 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2023-08-29 17:45:22 -0400 |
| commit | 6859d1f2902c600f6b1c587c91408a91e05cdc02 (patch) | |
| tree | e2930bdc74c22147444e9bcf843f3ac9e375398e /net/sunrpc/svc_xprt.c | |
| parent | d2f0ef1cbf37e396ef9c57a30c004ebe65cdbca9 (diff) | |
SUNRPC: make rqst_should_sleep() idempotent()
Based on its name you would think that rqst_should_sleep() would be
read-only, not changing anything. But in fact it will clear
SP_TASK_PENDING if that was set. This is surprising, and it blurs the
line between "check for work to do" and "dequeue work to do".
So change the "test_and_clear" to simple "test" and clear the bit once
the thread has decided to wake up and return to the caller.
With this, it makes sense to *always* set SP_TASK_PENDING when asked,
rather than to set it only if no thread could be woken up.
[ cel: Previously TASK_PENDING indicated there is work waiting but no
idle threads were found to pick up that work. After this patch, it acts
as an XPT_BUSY flag for wake-ups that have no associated xprt. ]
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net/sunrpc/svc_xprt.c')
| -rw-r--r-- | net/sunrpc/svc_xprt.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index d3280ae70e36..4cfe9640df48 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -581,8 +581,8 @@ void svc_wake_up(struct svc_serv *serv) { struct svc_pool *pool = &serv->sv_pools[0]; - if (!svc_pool_wake_idle_thread(pool)) - set_bit(SP_TASK_PENDING, &pool->sp_flags); + set_bit(SP_TASK_PENDING, &pool->sp_flags); + svc_pool_wake_idle_thread(pool); } EXPORT_SYMBOL_GPL(svc_wake_up); @@ -704,7 +704,7 @@ rqst_should_sleep(struct svc_rqst *rqstp) struct svc_pool *pool = rqstp->rq_pool; /* did someone call svc_wake_up? */ - if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) + if (test_bit(SP_TASK_PENDING, &pool->sp_flags)) return false; /* was a socket queued? */ @@ -748,6 +748,7 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp) set_bit(RQ_BUSY, &rqstp->rq_flags); smp_mb__after_atomic(); + clear_bit(SP_TASK_PENDING, &pool->sp_flags); rqstp->rq_xprt = svc_xprt_dequeue(pool); if (rqstp->rq_xprt) goto out_found; @@ -756,6 +757,7 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp) return NULL; return NULL; out_found: + clear_bit(SP_TASK_PENDING, &pool->sp_flags); /* Normally we will wait up to 5 seconds for any required * cache information to be provided. */ |