cfq-iosched: reset oom_cfqq in cfq_set_request()
authorVivek Goyal <vgoyal@redhat.com>
Thu, 9 Jul 2009 20:13:16 +0000 (22:13 +0200)
committerJens Axboe <axboe@carl.(none)>
Fri, 10 Jul 2009 18:31:54 +0000 (20:31 +0200)
In case memory is scarce, we now default to oom_cfqq. Once memory is
available again, we should allocate a new cfqq and stop using oom_cfqq for
a particular io context.

Once a new request comes in, check if we are using oom_cfqq, and if yes,
try to allocate a new cfqq.

Tested the patch by forcing the use of oom_cfqq and upon next request thread
realized that it was using oom_cfqq and it allocated a new cfqq.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block/cfq-iosched.c

index 87276eb83f7f54576fe8fc65c84605133b3e7000..fd7080ed793599127647baafbed009d8e11ef1af 100644 (file)
@@ -2311,7 +2311,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
                goto queue_fail;
 
        cfqq = cic_to_cfqq(cic, is_sync);
-       if (!cfqq) {
+       if (!cfqq || cfqq == &cfqd->oom_cfqq) {
                cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask);
                cic_set_cfqq(cic, cfqq, is_sync);
        }