On 10/27/2016 12:37 AM, Christoph Hellwig wrote:
* non-volatile media on completion.
+ * WRITE_BG Background write. This is for background activity like
+ * the periodic flush and background threshold writeback
*
*/
#define RW_MASK REQ_OP_WRITE
@@ -202,6 +204,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t
offset,
#define WRITE_FLUSH (REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH)
#define WRITE_FUA (REQ_SYNC | REQ_NOIDLE | REQ_FUA)
#define WRITE_FLUSH_FUA (REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH |
REQ_FUA)
+#define WRITE_BG (REQ_NOIDLE | REQ_BG)
I've been trying to kill off these WRITE_ flags as they aren't exactly
helpful, see my branch here that I'm waiting for the previous serious to
go in:
http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/block-flags
I'll just adapt to whatever goes in first, not really a concern for me.
Which also begs the question why you add the REQ_NOIDLE flag above, as
it's only applied to synchronous queues in cfq as far as I can tell.
Right, it's a CFQ hint. We only want to potentially idle for direct/sync
writes, not buffer async writeback.
And while I'm at nitpicking about the most trivial patch of the
series anyway: any good reason to not just spell out the "BACKGROUND" ?
Sure, I can make that change.
--
Jens Axboe
