From 1d2235152dc745c6d94bedb550fea84cffdbf768 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 2 Oct 2009 19:27:04 +0200 Subject: [PATCH] cfq-iosched: add a knob for desktop interactiveness This is basically identical to what Vivek Goyal posted, but combined into one and labelled 'desktop' instead of 'fairness'. The goal is to continue to improve on the latency side of things as it relates to interactiveness, keeping the questionable bits under this sysfs tunable so it would be easy for throughput-only people to turn off. Apart from adding the interactive sysfs knob, it also adds the behavioural change of allowing slice idling even if the hardware does tagged command queuing. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 1ca813b16e78..8917f2b3a783 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -173,6 +173,7 @@ struct cfq_data { unsigned int cfq_slice[2]; unsigned int cfq_slice_async_rq; unsigned int cfq_slice_idle; + unsigned int cfq_desktop; struct list_head cic_list; @@ -1951,7 +1952,7 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || - (cfqd->hw_tag && CIC_SEEKY(cic))) + (!cfqd->cfq_desktop && cfqd->hw_tag && CIC_SEEKY(cic))) enable_idle = 0; else if (sample_valid(cic->ttime_samples)) { if (cic->ttime_mean > cfqd->cfq_slice_idle) @@ -2480,6 +2481,7 @@ static void *cfq_init_queue(struct request_queue *q) cfqd->cfq_slice[1] = cfq_slice_sync; cfqd->cfq_slice_async_rq = cfq_slice_async_rq; cfqd->cfq_slice_idle = cfq_slice_idle; + cfqd->cfq_desktop = 1; cfqd->hw_tag = 1; return cfqd; @@ -2549,6 +2551,7 @@ SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); +SHOW_FUNCTION(cfq_desktop_show, cfqd->cfq_desktop, 0); #undef SHOW_FUNCTION #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ @@ -2580,6 +2583,7 @@ STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, UINT_MAX, 0); +STORE_FUNCTION(cfq_desktop_store, &cfqd->cfq_desktop, 0, 1, 0); #undef STORE_FUNCTION #define CFQ_ATTR(name) \ @@ -2595,6 +2599,7 @@ static struct elv_fs_entry cfq_attrs[] = { CFQ_ATTR(slice_async), CFQ_ATTR(slice_async_rq), CFQ_ATTR(slice_idle), + CFQ_ATTR(desktop), __ATTR_NULL }; -- GitLab