From 30bdf702604f304607ac8a986d7d89285c7141fa Mon Sep 17 00:00:00 2001 From: Corrado Zoccolo Date: Tue, 29 Jun 2010 10:48:21 +0200 Subject: [PATCH] cfq-iosched: fix tree-wide handling of rq_noidle Patch: 8e55063 cfq-iosched: fix corner cases in idling logic introduced the possibility of iding even on no-idle requests in the no_idle tree, if any previous request in the current slice could idle. The implementation had a problem, though: - if a queue sent several possibly idling requests and a noidle request as last one in the same time slice, the tree was still marked as idle. This patch fixes this misbehaviour, by using a 31-bucket hash to keep idling/non-idling status for queues in the noidle tree. Signed-off-by: Corrado Zoccolo --- block/cfq-iosched.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index d1ad066..5ef9a5d 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -214,7 +214,7 @@ struct cfq_data { enum wl_type_t serving_type; unsigned long workload_expires; struct cfq_group *serving_group; - bool noidle_tree_requires_idle; + u32 noidle_tree_requires_idle; /* * Each priority tree is sorted by next_request position. These @@ -2066,7 +2066,7 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) slice = max_t(unsigned, slice, CFQ_MIN_TT); cfq_log(cfqd, "workload slice:%d", slice); cfqd->workload_expires = jiffies + slice; - cfqd->noidle_tree_requires_idle = false; + cfqd->noidle_tree_requires_idle = 0U; } static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) @@ -3349,7 +3349,12 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) cfq_slice_expired(cfqd, 1); else if (sync && cfqq_empty && !cfq_close_cooperator(cfqd, cfqq)) { - cfqd->noidle_tree_requires_idle |= !rq_noidle(rq); + u32 bitmask = 1U << (((int)cfqq) % 31); + if (rq_noidle(rq)) + cfqd->noidle_tree_requires_idle &= ~bitmask; + else + cfqd->noidle_tree_requires_idle |= bitmask; + /* * Idling is enabled for SYNC_WORKLOAD. * SYNC_NOIDLE_WORKLOAD idles at the end of the tree -- 1.6.4.4