diff options
| author | Tejun Heo <tj@kernel.org> | 2012-10-04 17:13:28 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-06 03:04:58 +0900 |
| commit | 8290e2d2dcbf0d379d4b1379e17916515ee20a39 (patch) | |
| tree | b52a1e54446331aff7233ecdefdb8af479b33f5d | |
| parent | 17d7aac9a55b164874f3d4b7b4f5af87ab457b84 (diff) | |
scatterlist: atomic sg_mapping_iter() no longer needs disabled IRQs
SG mapping iterator w/ SG_MITER_ATOMIC set required IRQ disabled because
it originally used KM_BIO_SRC_IRQ to allow use from IRQ handlers.
kmap_atomic() has long been updated to handle stacking atomic mapping
requests on per-cpu basis and only requires not sleeping while mapped.
Update sg_mapping_iter such that atomic iterators only require disabling
preemption instead of disabling IRQ.
While at it, convert wte weird @ARG@ notations to @ARG in the comment of
sg_miter_start().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | lib/scatterlist.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/lib/scatterlist.c b/lib/scatterlist.c index fadae774a20c..e76d85cf3175 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -404,14 +404,13 @@ EXPORT_SYMBOL(sg_miter_start); * @miter: sg mapping iter to proceed * * Description: - * Proceeds @miter@ to the next mapping. @miter@ should have been - * started using sg_miter_start(). On successful return, - * @miter@->page, @miter@->addr and @miter@->length point to the - * current mapping. + * Proceeds @miter to the next mapping. @miter should have been started + * using sg_miter_start(). On successful return, @miter->page, + * @miter->addr and @miter->length point to the current mapping. * * Context: - * IRQ disabled if SG_MITER_ATOMIC. IRQ must stay disabled till - * @miter@ is stopped. May sleep if !SG_MITER_ATOMIC. + * Preemption disabled if SG_MITER_ATOMIC. Preemption must stay disabled + * till @miter is stopped. May sleep if !SG_MITER_ATOMIC. * * Returns: * true if @miter contains the next mapping. false if end of sg @@ -465,7 +464,8 @@ EXPORT_SYMBOL(sg_miter_next); * resources (kmap) need to be released during iteration. * * Context: - * IRQ disabled if the SG_MITER_ATOMIC is set. Don't care otherwise. + * Preemption disabled if the SG_MITER_ATOMIC is set. Don't care + * otherwise. */ void sg_miter_stop(struct sg_mapping_iter *miter) { @@ -479,7 +479,7 @@ void sg_miter_stop(struct sg_mapping_iter *miter) flush_kernel_dcache_page(miter->page); if (miter->__flags & SG_MITER_ATOMIC) { - WARN_ON(!irqs_disabled()); + WARN_ON_ONCE(preemptible()); kunmap_atomic(miter->addr); } else kunmap(miter->page); |