sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it

...also make the manipulation of sp_all_threads list use RCU-friendly
functions.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Tested-by: Chris Worley <chris.worley@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Jeff Layton 2014-11-21 14:19:28 -05:00 committed by J. Bruce Fields
parent 0b5707e452
commit 812443865c
3 changed files with 10 additions and 5 deletions

View File

@ -223,6 +223,7 @@ static inline void svc_putu32(struct kvec *iov, __be32 val)
struct svc_rqst {
struct list_head rq_list; /* idle list */
struct list_head rq_all; /* all threads list */
struct rcu_head rq_rcu_head; /* for RCU deferred kfree */
struct svc_xprt * rq_xprt; /* transport ptr */
struct sockaddr_storage rq_addr; /* peer address */
@ -262,6 +263,7 @@ struct svc_rqst {
#define RQ_SPLICE_OK (4) /* turned off in gss privacy
* to prevent encrypting page
* cache pages */
#define RQ_VICTIM (5) /* about to be shut down */
unsigned long rq_flags; /* flags field */
void * rq_argp; /* decoded arguments */

View File

@ -418,7 +418,8 @@ TRACE_EVENT(xs_tcp_data_recv,
{ (1UL << RQ_LOCAL), "RQ_LOCAL"}, \
{ (1UL << RQ_USEDEFERRAL), "RQ_USEDEFERRAL"}, \
{ (1UL << RQ_DROPME), "RQ_DROPME"}, \
{ (1UL << RQ_SPLICE_OK), "RQ_SPLICE_OK"})
{ (1UL << RQ_SPLICE_OK), "RQ_SPLICE_OK"}, \
{ (1UL << RQ_VICTIM), "RQ_VICTIM"})
TRACE_EVENT(svc_recv,
TP_PROTO(struct svc_rqst *rqst, int status),

View File

@ -616,7 +616,7 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
serv->sv_nrthreads++;
spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads++;
list_add(&rqstp->rq_all, &pool->sp_all_threads);
list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
spin_unlock_bh(&pool->sp_lock);
rqstp->rq_server = serv;
rqstp->rq_pool = pool;
@ -684,7 +684,8 @@ found_pool:
* so we don't try to kill it again.
*/
rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
list_del_init(&rqstp->rq_all);
set_bit(RQ_VICTIM, &rqstp->rq_flags);
list_del_rcu(&rqstp->rq_all);
task = rqstp->rq_task;
}
spin_unlock_bh(&pool->sp_lock);
@ -782,10 +783,11 @@ svc_exit_thread(struct svc_rqst *rqstp)
spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads--;
list_del(&rqstp->rq_all);
if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags))
list_del_rcu(&rqstp->rq_all);
spin_unlock_bh(&pool->sp_lock);
kfree(rqstp);
kfree_rcu(rqstp, rq_rcu_head);
/* Release the server */
if (serv)