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authorLatchesar Ionkov <lucho@ionkov.net>2006-01-08 01:05:00 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-08 20:14:06 -0800
commit531b1094b74365dcc55fa464d28a9a2497ae825d (patch)
treea0384dabe3be1c844166d028b3ef7c21c3dfe5fc /fs/9p/mux.c
parentd8da097afb765654c866062148fd98b11db9003e (diff)
downloadop-kernel-dev-531b1094b74365dcc55fa464d28a9a2497ae825d.zip
op-kernel-dev-531b1094b74365dcc55fa464d28a9a2497ae825d.tar.gz
[PATCH] v9fs: zero copy implementation
Performance enhancement reducing the number of copies in the data and stat paths. Signed-off-by: Latchesar Ionkov <lucho@ionkov.net> Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/9p/mux.c')
-rw-r--r--fs/9p/mux.c157
1 files changed, 86 insertions, 71 deletions
diff --git a/fs/9p/mux.c b/fs/9p/mux.c
index 62b6ad0..f21cf50 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);
+}
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