From ffc4e7595734cf768fa60cea8a4d545dfef8231a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 19 Feb 2008 10:02:29 +0100 Subject: cfq-iosched: add hlist for browsing parallel to the radix tree It's cumbersome to browse a radix tree from start to finish, especially since we modify keys when a process exits. So add a hlist for the single purpose of browsing over all known cfq_io_contexts, used for exit, io prio change, etc. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=9948 Signed-off-by: Jens Axboe --- block/blk-ioc.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) (limited to 'block/blk-ioc.c') diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 4ae0929c6e38..e34df7c9fc36 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -17,17 +17,13 @@ static struct kmem_cache *iocontext_cachep; static void cfq_dtor(struct io_context *ioc) { - struct cfq_io_context *cic[1]; - int r; + if (!hlist_empty(&ioc->cic_list)) { + struct cfq_io_context *cic; - /* - * We don't have a specific key to lookup with, so use the gang - * lookup to just retrieve the first item stored. The cfq exit - * function will iterate the full tree, so any member will do. - */ - r = radix_tree_gang_lookup(&ioc->radix_root, (void **) cic, 0, 1); - if (r > 0) - cic[0]->dtor(ioc); + cic = list_entry(ioc->cic_list.first, struct cfq_io_context, + cic_list); + cic->dtor(ioc); + } } /* @@ -57,18 +53,16 @@ EXPORT_SYMBOL(put_io_context); static void cfq_exit(struct io_context *ioc) { - struct cfq_io_context *cic[1]; - int r; - rcu_read_lock(); - /* - * See comment for cfq_dtor() - */ - r = radix_tree_gang_lookup(&ioc->radix_root, (void **) cic, 0, 1); - rcu_read_unlock(); - if (r > 0) - cic[0]->exit(ioc); + if (!hlist_empty(&ioc->cic_list)) { + struct cfq_io_context *cic; + + cic = list_entry(ioc->cic_list.first, struct cfq_io_context, + cic_list); + cic->exit(ioc); + } + rcu_read_unlock(); } /* Called by the exitting task */ @@ -105,6 +99,7 @@ struct io_context *alloc_io_context(gfp_t gfp_flags, int node) ret->nr_batch_requests = 0; /* because this is 0 */ ret->aic = NULL; INIT_RADIX_TREE(&ret->radix_root, GFP_ATOMIC | __GFP_HIGH); + INIT_HLIST_HEAD(&ret->cic_list); ret->ioc_data = NULL; } -- cgit v1.2.1