From 531b1094b74365dcc55fa464d28a9a2497ae825d Mon Sep 17 00:00:00 2001 From: Latchesar Ionkov Date: Sun, 8 Jan 2006 01:05:00 -0800 Subject: [PATCH] v9fs: zero copy implementation Performance enhancement reducing the number of copies in the data and stat paths. Signed-off-by: Latchesar Ionkov Cc: Eric Van Hensbergen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/9p/mux.c | 157 +++++++++++++++++++++++++++++++++--------------------------- 1 file changed, 86 insertions(+), 71 deletions(-) (limited to 'fs/9p/mux.c') diff --git a/fs/9p/mux.c b/fs/9p/mux.c index 62b6ad0767e..f21cf508397 100644 --- a/fs/9p/mux.c +++ b/fs/9p/mux.c @@ -35,8 +35,8 @@ #include "debug.h" #include "v9fs.h" #include "9p.h" -#include "transport.h" #include "conv.h" +#include "transport.h" #include "mux.h" #define ERREQFLUSH 1 @@ -74,6 +74,7 @@ struct v9fs_mux_data { wait_queue_head_t equeue; struct list_head req_list; struct list_head unsent_req_list; + struct v9fs_fcall *rcall; int rpos; char *rbuf; int wpos; @@ -101,11 +102,15 @@ struct v9fs_mux_rpc { wait_queue_head_t wqueue; }; +extern int v9fs_errstr2errno(char *str, int len); + static int v9fs_poll_proc(void *); static void v9fs_read_work(void *); static void v9fs_write_work(void *); static void v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address, poll_table * p); +static u16 v9fs_mux_get_tag(struct v9fs_mux_data *); +static void v9fs_mux_put_tag(struct v9fs_mux_data *, u16); static DECLARE_MUTEX(v9fs_mux_task_lock); static struct workqueue_struct *v9fs_mux_wq; @@ -166,8 +171,9 @@ static void v9fs_mux_poll_start(struct v9fs_mux_data *m) if (v9fs_mux_poll_tasks[i].task == NULL) { vpt = &v9fs_mux_poll_tasks[i]; dprintk(DEBUG_MUX, "create proc %p\n", vpt); - vpt->task = kthread_create(v9fs_poll_proc, - vpt, "v9fs-poll"); + vpt->task = + kthread_create(v9fs_poll_proc, vpt, + "v9fs-poll"); INIT_LIST_HEAD(&vpt->mux_list); vpt->muxnum = 0; v9fs_mux_poll_task_num++; @@ -253,7 +259,7 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize, struct v9fs_mux_data *m, *mtmp; dprintk(DEBUG_MUX, "transport %p msize %d\n", trans, msize); - m = kmalloc(sizeof(struct v9fs_mux_data) + 2 * msize, GFP_KERNEL); + m = kmalloc(sizeof(struct v9fs_mux_data), GFP_KERNEL); if (!m) return ERR_PTR(-ENOMEM); @@ -268,10 +274,11 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize, init_waitqueue_head(&m->equeue); INIT_LIST_HEAD(&m->req_list); INIT_LIST_HEAD(&m->unsent_req_list); + m->rcall = NULL; m->rpos = 0; - m->rbuf = (char *)m + sizeof(struct v9fs_mux_data); + m->rbuf = NULL; m->wpos = m->wsize = 0; - m->wbuf = m->rbuf + msize; + m->wbuf = NULL; INIT_WORK(&m->rq, v9fs_read_work, m); INIT_WORK(&m->wq, v9fs_write_work, m); m->wsched = 0; @@ -427,29 +434,6 @@ static int v9fs_poll_proc(void *a) return 0; } -static inline int v9fs_write_req(struct v9fs_mux_data *m, struct v9fs_req *req) -{ - int n; - - list_move_tail(&req->req_list, &m->req_list); - n = v9fs_serialize_fcall(req->tcall, m->wbuf, m->msize, *m->extended); - if (n < 0) { - req->err = n; - list_del(&req->req_list); - if (req->cb) { - spin_unlock(&m->lock); - (*req->cb) (req->cba, req->tcall, req->rcall, req->err); - req->cb = NULL; - spin_lock(&m->lock); - } else - kfree(req->rcall); - - kfree(req); - } - - return n; -} - /** * v9fs_write_work - called when a transport can send some data */ @@ -457,7 +441,7 @@ static void v9fs_write_work(void *a) { int n, err; struct v9fs_mux_data *m; - struct v9fs_req *req, *rtmp; + struct v9fs_req *req; m = a; @@ -472,17 +456,15 @@ static void v9fs_write_work(void *a) return; } - err = 0; spin_lock(&m->lock); - list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, - req_list) { - err = v9fs_write_req(m, req); - if (err > 0) - break; - } - - m->wsize = err; + req = + list_entry(m->unsent_req_list.next, struct v9fs_req, + req_list); + list_move_tail(&req->req_list, &m->req_list); + m->wbuf = req->tcall->sdata; + m->wsize = req->tcall->size; m->wpos = 0; + dump_data(m->wbuf, m->wsize); spin_unlock(&m->lock); } @@ -526,24 +508,23 @@ static void v9fs_write_work(void *a) static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req) { int ecode, tag; - char *ename; + struct v9fs_str *ename; tag = req->tag; if (req->rcall->id == RERROR && !req->err) { ecode = req->rcall->params.rerror.errno; - ename = req->rcall->params.rerror.error; + ename = &req->rcall->params.rerror.error; - dprintk(DEBUG_MUX, "Rerror %s\n", ename); + dprintk(DEBUG_MUX, "Rerror %.*s\n", ename->len, ename->str); if (*m->extended) req->err = -ecode; if (!req->err) { - req->err = v9fs_errstr2errno(ename); + req->err = v9fs_errstr2errno(ename->str, ename->len); if (!req->err) { /* string match failed */ - dprintk(DEBUG_ERROR, "unknown error: %s\n", - ename); + PRINT_FCALL_ERROR("unknown error", req->rcall); } if (!req->err) @@ -565,8 +546,7 @@ static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req) } else kfree(req->rcall); - if (tag != V9FS_NOTAG) - v9fs_put_idpool(tag, &m->tidpool); + v9fs_mux_put_tag(m, tag); wake_up(&m->equeue); kfree(req); @@ -577,10 +557,11 @@ static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req) */ static void v9fs_read_work(void *a) { - int n, err, rcallen; + int n, err; struct v9fs_mux_data *m; struct v9fs_req *req, *rptr, *rreq; struct v9fs_fcall *rcall; + char *rbuf; m = a; @@ -589,6 +570,19 @@ static void v9fs_read_work(void *a) rcall = NULL; dprintk(DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos); + + if (!m->rcall) { + m->rcall = + kmalloc(sizeof(struct v9fs_fcall) + m->msize, GFP_KERNEL); + if (!m->rcall) { + err = -ENOMEM; + goto error; + } + + m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall); + m->rpos = 0; + } + clear_bit(Rpending, &m->wsched); err = m->trans->read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos); dprintk(DEBUG_MUX, "mux %p got %d bytes\n", m, err); @@ -613,21 +607,32 @@ static void v9fs_read_work(void *a) if (m->rpos < n) break; - rcallen = n + V9FS_FCALLHDRSZ; - rcall = kmalloc(rcallen, GFP_KERNEL); - if (!rcall) { - err = -ENOMEM; - goto error; - } - dump_data(m->rbuf, n); - err = v9fs_deserialize_fcall(m->rbuf, n, rcall, rcallen, - *m->extended); + err = + v9fs_deserialize_fcall(m->rbuf, n, m->rcall, *m->extended); if (err < 0) { - kfree(rcall); goto error; } + rcall = m->rcall; + rbuf = m->rbuf; + if (m->rpos > n) { + m->rcall = kmalloc(sizeof(struct v9fs_fcall) + m->msize, + GFP_KERNEL); + if (!m->rcall) { + err = -ENOMEM; + goto error; + } + + m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall); + memmove(m->rbuf, rbuf + n, m->rpos - n); + m->rpos -= n; + } else { + m->rcall = NULL; + m->rbuf = NULL; + m->rpos = 0; + } + dprintk(DEBUG_MUX, "mux %p fcall id %d tag %d\n", m, rcall->id, rcall->tag); @@ -642,6 +647,7 @@ static void v9fs_read_work(void *a) process_request(m, req); break; } + } if (!req) { @@ -652,10 +658,6 @@ static void v9fs_read_work(void *a) m, rcall->id, rcall->tag); kfree(rcall); } - - if (m->rpos > n) - memmove(m->rbuf, m->rbuf + n, m->rpos - n); - m->rpos -= n; } if (!list_empty(&m->req_list)) { @@ -710,12 +712,13 @@ static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m, if (tc->id == TVERSION) n = V9FS_NOTAG; else - n = v9fs_get_idpool(&m->tidpool); + n = v9fs_mux_get_tag(m); if (n < 0) return ERR_PTR(-ENOMEM); - tc->tag = n; + v9fs_set_tag(tc, n); + req->tag = n; req->tcall = tc; req->rcall = NULL; @@ -773,9 +776,7 @@ v9fs_mux_flush_cb(void *a, struct v9fs_fcall *tc, struct v9fs_fcall *rc, if (!cb) spin_unlock(&m->lock); - if (v9fs_check_idpool(tag, &m->tidpool)) - v9fs_put_idpool(tag, &m->tidpool); - + v9fs_mux_put_tag(m, tag); kfree(tc); kfree(rc); } @@ -787,10 +788,7 @@ v9fs_mux_flush_request(struct v9fs_mux_data *m, struct v9fs_req *req) dprintk(DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag); - fc = kmalloc(sizeof(struct v9fs_fcall), GFP_KERNEL); - fc->id = TFLUSH; - fc->params.tflush.oldtag = req->tag; - + fc = v9fs_create_tflush(req->tag); v9fs_send_request(m, fc, v9fs_mux_flush_cb, m); } @@ -939,3 +937,20 @@ void v9fs_mux_cancel(struct v9fs_mux_data *m, int err) wake_up(&m->equeue); } + +static u16 v9fs_mux_get_tag(struct v9fs_mux_data *m) +{ + int tag; + + tag = v9fs_get_idpool(&m->tidpool); + if (tag < 0) + return V9FS_NOTAG; + else + return (u16) tag; +} + +static void v9fs_mux_put_tag(struct v9fs_mux_data *m, u16 tag) +{ + if (tag != V9FS_NOTAG && v9fs_check_idpool(tag, &m->tidpool)) + v9fs_put_idpool(tag, &m->tidpool); +} -- cgit v1.2.3