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| author | Jens Axboe <axboe@suse.de> | 2006-04-11 13:53:56 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@suse.de> | 2006-04-11 13:53:56 +0200 |
| commit | 6f767b0425f5902e4817648632230b512e81c963 (patch) | |
| tree | 2a8177c31617b4994a9ae5173b10653fb547e218 /fs/splice.c | |
| parent | 923f4f23940d2361e8d5c4245982163a8e9d1c91 (diff) | |
| download | linux-3.10-6f767b0425f5902e4817648632230b512e81c963.tar.gz linux-3.10-6f767b0425f5902e4817648632230b512e81c963.tar.bz2 linux-3.10-6f767b0425f5902e4817648632230b512e81c963.zip | |
[PATCH] splice: speedups and optimizations
- Kill the local variables that cache ->nrbufs, they just take up space.
- Only set do_wakeup for a real pipe. This is a big win for direct splicing.
- Kill i_mutex lock around ->f_pos update, regular io paths don't do this
either.
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'fs/splice.c')
| -rw-r--r-- | fs/splice.c | 33 |
1 files changed, 13 insertions, 20 deletions
diff --git a/fs/splice.c b/fs/splice.c index e30743c2c06..36bc262dfbd 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -150,8 +150,6 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, mutex_lock(&pipe->inode->i_mutex); for (;;) { - int bufs; - if (!pipe->readers) { send_sig(SIGPIPE, current, 0); if (!ret) @@ -159,9 +157,8 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, break; } - bufs = pipe->nrbufs; - if (bufs < PIPE_BUFFERS) { - int newbuf = (pipe->curbuf + bufs) & (PIPE_BUFFERS - 1); + if (pipe->nrbufs < PIPE_BUFFERS) { + int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1); struct pipe_buffer *buf = pipe->bufs + newbuf; struct page *page = pages[i++]; unsigned long this_len; @@ -174,8 +171,9 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, buf->offset = offset; buf->len = this_len; buf->ops = &page_cache_pipe_buf_ops; - pipe->nrbufs = ++bufs; - do_wakeup = 1; + pipe->nrbufs++; + if (pipe->inode) + do_wakeup = 1; ret += this_len; len -= this_len; @@ -184,7 +182,7 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, break; if (!len) break; - if (bufs < PIPE_BUFFERS) + if (pipe->nrbufs < PIPE_BUFFERS) continue; break; @@ -581,11 +579,8 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, mutex_lock(&pipe->inode->i_mutex); for (;;) { - int bufs = pipe->nrbufs; - - if (bufs) { - int curbuf = pipe->curbuf; - struct pipe_buffer *buf = pipe->bufs + curbuf; + if (pipe->nrbufs) { + struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; struct pipe_buf_operations *ops = buf->ops; sd.len = buf->len; @@ -606,10 +601,10 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, if (!buf->len) { buf->ops = NULL; ops->release(pipe, buf); - curbuf = (curbuf + 1) & (PIPE_BUFFERS - 1); - pipe->curbuf = curbuf; - pipe->nrbufs = --bufs; - do_wakeup = 1; + pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1); + pipe->nrbufs--; + if (pipe->inode) + do_wakeup = 1; } sd.pos += sd.len; @@ -618,7 +613,7 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, break; } - if (bufs) + if (pipe->nrbufs) continue; if (!pipe->writers) break; @@ -660,9 +655,7 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } - mutex_lock(&out->f_mapping->host->i_mutex); out->f_pos = sd.pos; - mutex_unlock(&out->f_mapping->host->i_mutex); return ret; } |