direct-io: inline the complete submission path
Add inlines to all the submission path functions. While this increases code size it also gives gcc a lot of optimization opportunities in this critical hotpath. In particular -- together with some other changes -- this allows gcc to get rid of the unnecessary clearing of sdio at the beginning and optimize the messy parameter passing. Any non inlining of a function which takes a sdio parameter would break this optimization because they cannot be done if the address of a structure is taken. Note that benefits are only seen with CONFIG_OPTIMIZE_INLINING and CONFIG_CC_OPTIMIZE_FOR_SIZE both set to off. This gives about 2.2% improvement on a large database benchmark with a high IOPS rate. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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@ -199,7 +199,7 @@ static inline unsigned dio_pages_present(struct dio_submit *sdio)
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/*
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* Go grab and pin some userspace pages. Typically we'll get 64 at a time.
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*/
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static int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
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static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
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{
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int ret;
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int nr_pages;
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@ -245,7 +245,8 @@ static int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
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* decent number of pages, less frequently. To provide nicer use of the
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* L1 cache.
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*/
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static struct page *dio_get_page(struct dio *dio, struct dio_submit *sdio)
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static inline struct page *dio_get_page(struct dio *dio,
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struct dio_submit *sdio)
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{
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if (dio_pages_present(sdio) == 0) {
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int ret;
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@ -376,7 +377,7 @@ void dio_end_io(struct bio *bio, int error)
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}
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EXPORT_SYMBOL_GPL(dio_end_io);
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static void
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static inline void
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dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
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struct block_device *bdev,
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sector_t first_sector, int nr_vecs)
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@ -407,7 +408,7 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
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*
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* bios hold a dio reference between submit_bio and ->end_io.
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*/
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static void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
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static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
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{
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struct bio *bio = sdio->bio;
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unsigned long flags;
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@ -435,7 +436,7 @@ static void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
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/*
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* Release any resources in case of a failure
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*/
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static void dio_cleanup(struct dio *dio, struct dio_submit *sdio)
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static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio)
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{
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while (dio_pages_present(sdio))
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page_cache_release(dio_get_page(dio, sdio));
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@ -528,7 +529,7 @@ static void dio_await_completion(struct dio *dio)
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*
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* This also helps to limit the peak amount of pinned userspace memory.
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*/
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static int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)
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static inline int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)
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{
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int ret = 0;
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@ -631,8 +632,8 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
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/*
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* There is no bio. Make one now.
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*/
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static int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
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sector_t start_sector, struct buffer_head *map_bh)
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static inline int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
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sector_t start_sector, struct buffer_head *map_bh)
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{
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sector_t sector;
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int ret, nr_pages;
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@ -657,7 +658,7 @@ static int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
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*
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* Return zero on success. Non-zero means the caller needs to start a new BIO.
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*/
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static int dio_bio_add_page(struct dio_submit *sdio)
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static inline int dio_bio_add_page(struct dio_submit *sdio)
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{
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int ret;
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@ -689,8 +690,8 @@ static int dio_bio_add_page(struct dio_submit *sdio)
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* The caller of this function is responsible for removing cur_page from the
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* dio, and for dropping the refcount which came from that presence.
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*/
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static int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
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struct buffer_head *map_bh)
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static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
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struct buffer_head *map_bh)
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{
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int ret = 0;
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@ -759,7 +760,7 @@ static int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
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* If that doesn't work out then we put the old page into the bio and add this
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* page to the dio instead.
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*/
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static int
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static inline int
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submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
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unsigned offset, unsigned len, sector_t blocknr,
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struct buffer_head *map_bh)
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@ -842,8 +843,8 @@ static void clean_blockdev_aliases(struct dio *dio, struct buffer_head *map_bh)
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* `end' is zero if we're doing the start of the IO, 1 at the end of the
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* IO.
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*/
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static void dio_zero_block(struct dio *dio, struct dio_submit *sdio, int end,
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struct buffer_head *map_bh)
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static inline void dio_zero_block(struct dio *dio, struct dio_submit *sdio,
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int end, struct buffer_head *map_bh)
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{
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unsigned dio_blocks_per_fs_block;
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unsigned this_chunk_blocks; /* In dio_blocks */
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@ -1042,7 +1043,7 @@ static int do_direct_IO(struct dio *dio, struct dio_submit *sdio,
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return ret;
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}
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static ssize_t
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static inline ssize_t
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direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
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const struct iovec *iov, loff_t offset, unsigned long nr_segs,
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unsigned blkbits, get_block_t get_block, dio_iodone_t end_io,
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@ -1216,6 +1217,11 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
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* expected that filesystem provide exclusion between new direct I/O
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* and truncates. For DIO_LOCKING filesystems this is done by i_mutex,
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* but other filesystems need to take care of this on their own.
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*
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* NOTE: if you pass "sdio" to anything by pointer make sure that function
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* is always inlined. Otherwise gcc is unable to split the structure into
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* individual fields and will generate much worse code. This is important
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* for the whole file.
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*/
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ssize_t
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__blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
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