From: Jan Kara <jack@suse.cz> To: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Kara <jack@suse.cz>, LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/6] lib: Implement range locks Date: Mon, 4 Feb 2013 17:41:42 +0100 [thread overview] Message-ID: <20130204164142.GG7523@quack.suse.cz> (raw) In-Reply-To: <20130131155726.05d09b21.akpm@linux-foundation.org> On Thu 31-01-13 15:57:26, Andrew Morton wrote: > On Thu, 31 Jan 2013 22:49:49 +0100 > Jan Kara <jack@suse.cz> wrote: > > > Implement range locking using interval tree. > > > > ... > > > > +void range_lock(struct range_lock_tree *tree, struct range_lock *lock) > > +{ > > + struct interval_tree_node *node; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&tree->lock, flags); > > + node = interval_tree_iter_first(&tree->root, lock->node.start, > > + lock->node.last); > > + while (node) { > > + lock->blocking_ranges++; > > + node = interval_tree_iter_next(node, lock->node.start, > > + lock->node.last); > > + } > > + interval_tree_insert(&lock->node, &tree->root); > > + /* Do we need to go to sleep? */ > > + while (lock->blocking_ranges) { > > + lock->task = current; > > + __set_current_state(TASK_UNINTERRUPTIBLE); > > + spin_unlock_irqrestore(&tree->lock, flags); > > + schedule(); > > + spin_lock_irqsave(&tree->lock, flags); > > + } > > + spin_unlock_irqrestore(&tree->lock, flags); > > +} > > > > ... > > > > +void range_unlock(struct range_lock_tree *tree, struct range_lock *lock) > > +{ > > + struct interval_tree_node *node; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&tree->lock, flags); > > + interval_tree_remove(&lock->node, &tree->root); > > + node = interval_tree_iter_first(&tree->root, lock->node.start, > > + lock->node.last); > > + while (node) { > > + range_lock_unblock((struct range_lock *)node); > > + node = interval_tree_iter_next(node, lock->node.start, > > + lock->node.last); > > + } > > + spin_unlock_irqrestore(&tree->lock, flags); > > +} > > What are the worst-case interrupt-off durations here? Good question. In theory, it could be relatively long, e.g. when there are lots of DIOs in flight against a range which is locked. I'll do some measurements to get some idea. > I note that the new exported functions in this patchset are > refreshingly free of documentation ;) They are *so* obvious ;) Point taken... Thanks for review. Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR
WARNING: multiple messages have this Message-ID (diff)
From: Jan Kara <jack@suse.cz> To: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Kara <jack@suse.cz>, LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/6] lib: Implement range locks Date: Mon, 4 Feb 2013 17:41:42 +0100 [thread overview] Message-ID: <20130204164142.GG7523@quack.suse.cz> (raw) In-Reply-To: <20130131155726.05d09b21.akpm@linux-foundation.org> On Thu 31-01-13 15:57:26, Andrew Morton wrote: > On Thu, 31 Jan 2013 22:49:49 +0100 > Jan Kara <jack@suse.cz> wrote: > > > Implement range locking using interval tree. > > > > ... > > > > +void range_lock(struct range_lock_tree *tree, struct range_lock *lock) > > +{ > > + struct interval_tree_node *node; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&tree->lock, flags); > > + node = interval_tree_iter_first(&tree->root, lock->node.start, > > + lock->node.last); > > + while (node) { > > + lock->blocking_ranges++; > > + node = interval_tree_iter_next(node, lock->node.start, > > + lock->node.last); > > + } > > + interval_tree_insert(&lock->node, &tree->root); > > + /* Do we need to go to sleep? */ > > + while (lock->blocking_ranges) { > > + lock->task = current; > > + __set_current_state(TASK_UNINTERRUPTIBLE); > > + spin_unlock_irqrestore(&tree->lock, flags); > > + schedule(); > > + spin_lock_irqsave(&tree->lock, flags); > > + } > > + spin_unlock_irqrestore(&tree->lock, flags); > > +} > > > > ... > > > > +void range_unlock(struct range_lock_tree *tree, struct range_lock *lock) > > +{ > > + struct interval_tree_node *node; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&tree->lock, flags); > > + interval_tree_remove(&lock->node, &tree->root); > > + node = interval_tree_iter_first(&tree->root, lock->node.start, > > + lock->node.last); > > + while (node) { > > + range_lock_unblock((struct range_lock *)node); > > + node = interval_tree_iter_next(node, lock->node.start, > > + lock->node.last); > > + } > > + spin_unlock_irqrestore(&tree->lock, flags); > > +} > > What are the worst-case interrupt-off durations here? Good question. In theory, it could be relatively long, e.g. when there are lots of DIOs in flight against a range which is locked. I'll do some measurements to get some idea. > I note that the new exported functions in this patchset are > refreshingly free of documentation ;) They are *so* obvious ;) Point taken... Thanks for review. Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-02-04 16:41 UTC|newest] Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-01-31 21:49 [PATCH 0/6 RFC] Mapping range lock Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-01-31 21:49 ` [PATCH 1/6] lib: Implement range locks Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-01-31 23:57 ` Andrew Morton 2013-01-31 23:57 ` Andrew Morton 2013-02-04 16:41 ` Jan Kara [this message] 2013-02-04 16:41 ` Jan Kara 2013-02-11 5:42 ` Michel Lespinasse 2013-02-11 5:42 ` Michel Lespinasse 2013-02-11 10:27 ` Jan Kara 2013-02-11 10:27 ` Jan Kara 2013-02-11 11:03 ` Michel Lespinasse 2013-02-11 11:03 ` Michel Lespinasse 2013-02-11 12:58 ` Jan Kara 2013-02-11 12:58 ` Jan Kara 2013-01-31 21:49 ` [PATCH 2/6] fs: Take mapping lock in generic read paths Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-01-31 23:59 ` Andrew Morton 2013-01-31 23:59 ` Andrew Morton 2013-02-04 12:47 ` Jan Kara 2013-02-04 12:47 ` Jan Kara 2013-02-08 14:59 ` Jan Kara 2013-02-08 14:59 ` Jan Kara 2013-01-31 21:49 ` [PATCH 3/6] fs: Provide function to take mapping lock in buffered write path Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-01-31 21:49 ` [PATCH 4/6] fs: Don't call dio_cleanup() before submitting all bios Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-01-31 21:49 ` [PATCH 5/6] fs: Take mapping lock during direct IO Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-01-31 21:49 ` [PATCH 6/6] ext3: Convert ext3 to use mapping lock Jan Kara 2013-01-31 21:49 ` Jan Kara 2013-02-01 0:07 ` [PATCH 0/6 RFC] Mapping range lock Andrew Morton 2013-02-01 0:07 ` Andrew Morton 2013-02-04 9:29 ` Zheng Liu 2013-02-04 9:29 ` Zheng Liu 2013-02-04 12:38 ` Jan Kara 2013-02-04 12:38 ` Jan Kara 2013-02-05 23:25 ` Dave Chinner 2013-02-05 23:25 ` Dave Chinner 2013-02-06 19:25 ` Jan Kara 2013-02-06 19:25 ` Jan Kara 2013-02-07 2:43 ` Dave Chinner 2013-02-07 2:43 ` Dave Chinner 2013-02-07 11:06 ` Jan Kara 2013-02-07 11:06 ` Jan Kara
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