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| author | Jens Axboe <axboe@suse.de> | 2006-03-28 08:59:01 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@suse.de> | 2006-03-28 08:59:01 +0200 |
| commit | e2d74ac0664c89757bde8fb18c98cd7bf53da61c (patch) | |
| tree | 1e858044a9180766eae4ec694d4200c4ae850406 /block/ll_rw_blk.c | |
| parent | 329b10bb0feacb7fb9a41389313ff0a51ae56f2a (diff) | |
| download | linux-e2d74ac0664c89757bde8fb18c98cd7bf53da61c.tar.gz linux-e2d74ac0664c89757bde8fb18c98cd7bf53da61c.tar.bz2 linux-e2d74ac0664c89757bde8fb18c98cd7bf53da61c.zip | |
[PATCH] [BLOCK] cfq-iosched: change cfq io context linking from list to tree
On setups with many disks, we spend a considerable amount of time
looking up the process-disk mapping on each queue of io. Testing with
a NULL based block driver, this costs 40-50% reduction in throughput
for 1000 disks.
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block/ll_rw_blk.c')
| -rw-r--r-- | block/ll_rw_blk.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 82469db25100..cb608768ca37 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3539,11 +3539,15 @@ void put_io_context(struct io_context *ioc) BUG_ON(atomic_read(&ioc->refcount) == 0); if (atomic_dec_and_test(&ioc->refcount)) { + struct cfq_io_context *cic; + rcu_read_lock(); if (ioc->aic && ioc->aic->dtor) ioc->aic->dtor(ioc->aic); - if (ioc->cic && ioc->cic->dtor) - ioc->cic->dtor(ioc->cic); + if (ioc->cic_root.rb_node != NULL) { + cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node); + cic->dtor(ioc); + } rcu_read_unlock(); kmem_cache_free(iocontext_cachep, ioc); @@ -3556,6 +3560,7 @@ void exit_io_context(void) { unsigned long flags; struct io_context *ioc; + struct cfq_io_context *cic; local_irq_save(flags); task_lock(current); @@ -3567,9 +3572,11 @@ void exit_io_context(void) if (ioc->aic && ioc->aic->exit) ioc->aic->exit(ioc->aic); - if (ioc->cic && ioc->cic->exit) - ioc->cic->exit(ioc->cic); - + if (ioc->cic_root.rb_node != NULL) { + cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node); + cic->exit(ioc); + } + put_io_context(ioc); } @@ -3598,7 +3605,7 @@ struct io_context *current_io_context(gfp_t gfp_flags) ret->last_waited = jiffies; /* doesn't matter... */ ret->nr_batch_requests = 0; /* because this is 0 */ ret->aic = NULL; - ret->cic = NULL; + ret->cic_root.rb_node = NULL; tsk->io_context = ret; } |