diff options
| author | NeilBrown <neilb@suse.de> | 2023-09-11 10:39:11 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2023-10-16 12:44:04 -0400 |
| commit | 5ff817b23534dd3942f881ab01dd5050505517aa (patch) | |
| tree | 68645765fa9aa791b5ccd0f39dc687ab2d1b8b6e /net/sunrpc/svc_xprt.c | |
| parent | fa341560ca7458f4396d5a0771cb5f2358d8535d (diff) | |
SUNRPC: add list of idle threads
Rather than searching a list of threads to find an idle one, having a
list of idle threads allows an idle thread to be found immediately.
This adds some spin_lock calls which is not ideal, but as the hold-time
is tiny it is still faster than searching a list. A future patch will
remove them using llist.h. This involves some subtlety and so is left
to a separate patch.
This removes the need for the RQ_BUSY flag. The rqst is "busy"
precisely when it is not on the "idle" list.
Signed-off-by: NeilBrown <neilb@suse.de>
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 | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index b8539545fefd..ebfeeb504a79 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -737,8 +737,9 @@ static void svc_rqst_wait_for_work(struct svc_rqst *rqstp) set_current_state(TASK_IDLE); smp_mb__before_atomic(); clear_bit(SP_CONGESTED, &pool->sp_flags); - clear_bit(RQ_BUSY, &rqstp->rq_flags); - smp_mb__after_atomic(); + spin_lock_bh(&pool->sp_lock); + list_add(&rqstp->rq_idle, &pool->sp_idle_threads); + spin_unlock_bh(&pool->sp_lock); /* Need to check should_sleep() again after * setting task state in case a wakeup happened @@ -751,8 +752,14 @@ static void svc_rqst_wait_for_work(struct svc_rqst *rqstp) cond_resched(); } - set_bit(RQ_BUSY, &rqstp->rq_flags); - smp_mb__after_atomic(); + /* We *must* be removed from the list before we can continue. + * If we were woken, this is already done + */ + if (!svc_thread_busy(rqstp)) { + spin_lock_bh(&pool->sp_lock); + list_del_init(&rqstp->rq_idle); + spin_unlock_bh(&pool->sp_lock); + } } else { cond_resched(); } |