| Message ID | 1477515135-16469-2-git-send-email-axboe@fb.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> * 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 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. 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" ? -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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.
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index cd395ecec99d..765994c5b2c5 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -162,6 +162,7 @@ enum rq_flag_bits { __REQ_INTEGRITY, /* I/O includes block integrity payload */ __REQ_FUA, /* forced unit access */ __REQ_PREFLUSH, /* request for cache flush */ + __REQ_BG, /* background activity */ /* bio only flags */ __REQ_RAHEAD, /* read ahead, can fail anytime */ @@ -205,7 +206,7 @@ enum rq_flag_bits { (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) #define REQ_COMMON_MASK \ (REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | REQ_NOIDLE | \ - REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE) + REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE | REQ_BG) #define REQ_CLONE_MASK REQ_COMMON_MASK /* This mask is used for both bio and request merge checking */ @@ -230,6 +231,7 @@ enum rq_flag_bits { #define REQ_COPY_USER (1ULL << __REQ_COPY_USER) #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH) #define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ) +#define REQ_BG (1ULL << __REQ_BG) #define REQ_IO_STAT (1ULL << __REQ_IO_STAT) #define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE) #define REQ_PM (1ULL << __REQ_PM) diff --git a/include/linux/fs.h b/include/linux/fs.h index 16d2b6e874d6..baaedb05e5b2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -189,6 +189,8 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded * by a cache flush and data is guaranteed to be on * 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) /* * Attribute flags. These should be or-ed together to figure out what
This adds a new request flag, REQ_BG, that callers can use to tell the block layer that this is background (non-urgent) IO. Signed-off-by: Jens Axboe <axboe@fb.com> --- include/linux/blk_types.h | 4 +++- include/linux/fs.h | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-)