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| author | Shaohua Li writes <shaohua.li@intel.com> | 2010-12-13 14:32:22 +0100 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-12-13 14:32:22 +0100 |
| commit | e4ea0c16a85d221ebcc3a21f32e321440459e0fc (patch) | |
| tree | 47acf4da84f9a448e6eb6172a5440ccc60696ed9 /block | |
| parent | 760701bfe14faee8ea0608a9cab2046071d98a39 (diff) | |
| download | linux-e4ea0c16a85d221ebcc3a21f32e321440459e0fc.tar.gz linux-e4ea0c16a85d221ebcc3a21f32e321440459e0fc.tar.bz2 linux-e4ea0c16a85d221ebcc3a21f32e321440459e0fc.zip | |
block cfq: select new workload if priority changed
If priority is changed, continuing to check workload_expires and service tree
count of the previous workload does not make sense. We should always choose
the workload with lowest key of new priority in such case.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/cfq-iosched.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 5d0349d602fe..9b186fd6bf47 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2101,6 +2101,7 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) unsigned count; struct cfq_rb_root *st; unsigned group_slice; + enum wl_prio_t original_prio = cfqd->serving_prio; if (!cfqg) { cfqd->serving_prio = IDLE_WORKLOAD; @@ -2119,6 +2120,9 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) return; } + if (original_prio != cfqd->serving_prio) + goto new_workload; + /* * For RT and BE, we have to choose also the type * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload @@ -2133,6 +2137,7 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) if (count && !time_after(jiffies, cfqd->workload_expires)) return; +new_workload: /* otherwise select new workload type */ cfqd->serving_type = cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio); |