Mercurial > hg > nginx
changeset 4233:aae172db7ac8
Event pipe: reduced number of file buffers used.
If possible we now just extend already present file buffer in p->out chain
instead of keeping ngx_buf_t for each buffer we've flushed to disk. This
saves about 120 bytes of memory per buffer flushed to disk, and resolves
high CPU usage observed in edge cases (due to coalescing these buffers on
send).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 31 Oct 2011 09:54:55 +0000 |
parents | 487ab473f393 |
children | d5462eab1440 |
files | src/event/ngx_event_pipe.c src/event/ngx_event_pipe.h |
diffstat | 2 files changed, 59 insertions(+), 26 deletions(-) [+] |
line wrap: on
line diff
--- a/src/event/ngx_event_pipe.c Mon Oct 31 09:53:16 2011 +0000 +++ b/src/event/ngx_event_pipe.c Mon Oct 31 09:54:55 2011 +0000 @@ -680,10 +680,10 @@ static ngx_int_t ngx_event_pipe_write_chain_to_temp_file(ngx_event_pipe_t *p) { - ssize_t size, bsize; + ssize_t size, bsize, n; ngx_buf_t *b; ngx_uint_t prev_last_shadow; - ngx_chain_t *cl, *tl, *next, *out, **ll, **last_free, fl; + ngx_chain_t *cl, *tl, *next, *out, **ll, **last_out, **last_free, fl; if (p->buf_to_file) { fl.buf = p->buf_to_file; @@ -748,10 +748,63 @@ p->last_in = &p->in; } - if (ngx_write_chain_to_temp_file(p->temp_file, out) == NGX_ERROR) { + n = ngx_write_chain_to_temp_file(p->temp_file, out); + + if (n == NGX_ERROR) { return NGX_ABORT; } + if (p->buf_to_file) { + p->temp_file->offset = p->buf_to_file->last - p->buf_to_file->pos; + n -= p->buf_to_file->last - p->buf_to_file->pos; + p->buf_to_file = NULL; + out = out->next; + } + + if (n > 0) { + /* update previous buffer or add new buffer */ + + if (p->out) { + for (cl = p->out; cl->next; cl = cl->next) { /* void */ } + + b = cl->buf; + + if (b->file_last == p->temp_file->offset) { + p->temp_file->offset += n; + b->file_last = p->temp_file->offset; + goto free; + } + + last_out = &cl->next; + + } else { + last_out = &p->out; + } + + cl = ngx_chain_get_free_buf(p->pool, &p->free); + if (cl == NULL) { + return NGX_ABORT; + } + + b = cl->buf; + + ngx_memzero(b, sizeof(ngx_buf_t)); + + b->tag = p->tag; + + b->file = &p->temp_file->file; + b->file_pos = p->temp_file->offset; + p->temp_file->offset += n; + b->file_last = p->temp_file->offset; + + b->in_file = 1; + b->temp_file = 1; + + *last_out = cl; + } + +free: + for (last_free = &p->free_raw_bufs; *last_free != NULL; last_free = &(*last_free)->next) @@ -759,31 +812,13 @@ /* void */ } - if (p->buf_to_file) { - p->temp_file->offset = p->buf_to_file->last - p->buf_to_file->pos; - p->buf_to_file = NULL; - out = out->next; - } - for (cl = out; cl; cl = next) { next = cl->next; - cl->next = NULL; + + cl->next = p->free; + p->free = cl; b = cl->buf; - b->file = &p->temp_file->file; - b->file_pos = p->temp_file->offset; - p->temp_file->offset += b->last - b->pos; - b->file_last = p->temp_file->offset; - - b->in_file = 1; - b->temp_file = 1; - - if (p->out) { - *p->last_out = cl; - } else { - p->out = cl; - } - p->last_out = &cl->next; if (b->last_shadow) {