forked from Minki/linux
NFS: Replace atomic_t variables in nfs_direct_req with a single spin lock
Three atomic_t variables cause a lot of bus locking. Because they are all used in the same places in the code, just use a single spin lock. Now that the atomic_t variables are gone, we can remove the request size limitation since the code no longer depends on the limited width of atomic_t on some platforms. Test plan: Compile with CONFIG_NFS and CONFIG_NFS_DIRECTIO enabled. Millions of fsx operations, iozone, OraSim. Signed-off-by: Chuck Lever <cel@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever
Trond Myklebust
parent
88467055f7
commit
15ce4a0c1c
@ -58,7 +58,6 @@
|
||||
#include "iostat.h"
|
||||
|
||||
#define NFSDBG_FACILITY NFSDBG_VFS
|
||||
#define MAX_DIRECTIO_SIZE (4096UL << PAGE_SHIFT)
|
||||
|
||||
static void nfs_free_user_pages(struct page **pages, int npages, int do_dirty);
|
||||
static kmem_cache_t *nfs_direct_cachep;
|
||||
@ -68,6 +67,8 @@ static kmem_cache_t *nfs_direct_cachep;
|
||||
*/
|
||||
struct nfs_direct_req {
|
||||
struct kref kref; /* release manager */
|
||||
|
||||
/* I/O parameters */
|
||||
struct list_head list; /* nfs_read/write_data structs */
|
||||
struct file * filp; /* file descriptor */
|
||||
struct kiocb * iocb; /* controlling i/o request */
|
||||
@ -75,12 +76,14 @@ struct nfs_direct_req {
|
||||
struct inode * inode; /* target file of i/o */
|
||||
struct page ** pages; /* pages in our buffer */
|
||||
unsigned int npages; /* count of pages */
|
||||
atomic_t complete, /* i/os we're waiting for */
|
||||
count, /* bytes actually processed */
|
||||
|
||||
/* completion state */
|
||||
spinlock_t lock; /* protect completion state */
|
||||
int outstanding; /* i/os we're waiting for */
|
||||
ssize_t count, /* bytes actually processed */
|
||||
error; /* any reported error */
|
||||
};
|
||||
|
||||
|
||||
/**
|
||||
* nfs_direct_IO - NFS address space operation for direct I/O
|
||||
* @rw: direction (read or write)
|
||||
@ -110,12 +113,6 @@ static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t siz
|
||||
unsigned long page_count;
|
||||
size_t array_size;
|
||||
|
||||
/* set an arbitrary limit to prevent type overflow */
|
||||
if (size > MAX_DIRECTIO_SIZE) {
|
||||
*pages = NULL;
|
||||
return -EFBIG;
|
||||
}
|
||||
|
||||
page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
||||
page_count -= user_addr >> PAGE_SHIFT;
|
||||
|
||||
@ -164,8 +161,10 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
|
||||
init_waitqueue_head(&dreq->wait);
|
||||
INIT_LIST_HEAD(&dreq->list);
|
||||
dreq->iocb = NULL;
|
||||
atomic_set(&dreq->count, 0);
|
||||
atomic_set(&dreq->error, 0);
|
||||
spin_lock_init(&dreq->lock);
|
||||
dreq->outstanding = 0;
|
||||
dreq->count = 0;
|
||||
dreq->error = 0;
|
||||
|
||||
return dreq;
|
||||
}
|
||||
@ -181,19 +180,18 @@ static void nfs_direct_req_release(struct kref *kref)
|
||||
*/
|
||||
static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq)
|
||||
{
|
||||
int result = -EIOCBQUEUED;
|
||||
ssize_t result = -EIOCBQUEUED;
|
||||
|
||||
/* Async requests don't wait here */
|
||||
if (dreq->iocb)
|
||||
goto out;
|
||||
|
||||
result = wait_event_interruptible(dreq->wait,
|
||||
(atomic_read(&dreq->complete) == 0));
|
||||
result = wait_event_interruptible(dreq->wait, (dreq->outstanding == 0));
|
||||
|
||||
if (!result)
|
||||
result = atomic_read(&dreq->error);
|
||||
result = dreq->error;
|
||||
if (!result)
|
||||
result = atomic_read(&dreq->count);
|
||||
result = dreq->count;
|
||||
|
||||
out:
|
||||
kref_put(&dreq->kref, nfs_direct_req_release);
|
||||
@ -214,9 +212,9 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq)
|
||||
nfs_free_user_pages(dreq->pages, dreq->npages, 1);
|
||||
|
||||
if (dreq->iocb) {
|
||||
long res = atomic_read(&dreq->error);
|
||||
long res = (long) dreq->error;
|
||||
if (!res)
|
||||
res = atomic_read(&dreq->count);
|
||||
res = (long) dreq->count;
|
||||
aio_complete(dreq->iocb, res, 0);
|
||||
} else
|
||||
wake_up(&dreq->wait);
|
||||
@ -233,7 +231,6 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize)
|
||||
{
|
||||
struct list_head *list;
|
||||
struct nfs_direct_req *dreq;
|
||||
unsigned int reads = 0;
|
||||
unsigned int rpages = (rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
|
||||
|
||||
dreq = nfs_direct_req_alloc();
|
||||
@ -259,13 +256,12 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize)
|
||||
list_add(&data->pages, list);
|
||||
|
||||
data->req = (struct nfs_page *) dreq;
|
||||
reads++;
|
||||
dreq->outstanding++;
|
||||
if (nbytes <= rsize)
|
||||
break;
|
||||
nbytes -= rsize;
|
||||
}
|
||||
kref_get(&dreq->kref);
|
||||
atomic_set(&dreq->complete, reads);
|
||||
return dreq;
|
||||
}
|
||||
|
||||
@ -276,13 +272,21 @@ static void nfs_direct_read_result(struct rpc_task *task, void *calldata)
|
||||
|
||||
if (nfs_readpage_result(task, data) != 0)
|
||||
return;
|
||||
if (likely(task->tk_status >= 0))
|
||||
atomic_add(data->res.count, &dreq->count);
|
||||
else
|
||||
atomic_set(&dreq->error, task->tk_status);
|
||||
|
||||
if (unlikely(atomic_dec_and_test(&dreq->complete)))
|
||||
nfs_direct_complete(dreq);
|
||||
spin_lock(&dreq->lock);
|
||||
|
||||
if (likely(task->tk_status >= 0))
|
||||
dreq->count += data->res.count;
|
||||
else
|
||||
dreq->error = task->tk_status;
|
||||
|
||||
if (--dreq->outstanding) {
|
||||
spin_unlock(&dreq->lock);
|
||||
return;
|
||||
}
|
||||
|
||||
spin_unlock(&dreq->lock);
|
||||
nfs_direct_complete(dreq);
|
||||
}
|
||||
|
||||
static const struct rpc_call_ops nfs_read_direct_ops = {
|
||||
@ -388,7 +392,6 @@ static struct nfs_direct_req *nfs_direct_write_alloc(size_t nbytes, size_t wsize
|
||||
{
|
||||
struct list_head *list;
|
||||
struct nfs_direct_req *dreq;
|
||||
unsigned int writes = 0;
|
||||
unsigned int wpages = (wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
|
||||
|
||||
dreq = nfs_direct_req_alloc();
|
||||
@ -414,16 +417,19 @@ static struct nfs_direct_req *nfs_direct_write_alloc(size_t nbytes, size_t wsize
|
||||
list_add(&data->pages, list);
|
||||
|
||||
data->req = (struct nfs_page *) dreq;
|
||||
writes++;
|
||||
dreq->outstanding++;
|
||||
if (nbytes <= wsize)
|
||||
break;
|
||||
nbytes -= wsize;
|
||||
}
|
||||
kref_get(&dreq->kref);
|
||||
atomic_set(&dreq->complete, writes);
|
||||
return dreq;
|
||||
}
|
||||
|
||||
/*
|
||||
* NB: Return the value of the first error return code. Subsequent
|
||||
* errors after the first one are ignored.
|
||||
*/
|
||||
static void nfs_direct_write_result(struct rpc_task *task, void *calldata)
|
||||
{
|
||||
struct nfs_write_data *data = calldata;
|
||||
@ -436,15 +442,22 @@ static void nfs_direct_write_result(struct rpc_task *task, void *calldata)
|
||||
if (unlikely(data->res.verf->committed != NFS_FILE_SYNC))
|
||||
status = -EIO;
|
||||
|
||||
if (likely(status >= 0))
|
||||
atomic_add(data->res.count, &dreq->count);
|
||||
else
|
||||
atomic_set(&dreq->error, status);
|
||||
spin_lock(&dreq->lock);
|
||||
|
||||
if (unlikely(atomic_dec_and_test(&dreq->complete))) {
|
||||
nfs_end_data_update(data->inode);
|
||||
nfs_direct_complete(dreq);
|
||||
if (likely(status >= 0))
|
||||
dreq->count += data->res.count;
|
||||
else
|
||||
dreq->error = status;
|
||||
|
||||
if (--dreq->outstanding) {
|
||||
spin_unlock(&dreq->lock);
|
||||
return;
|
||||
}
|
||||
|
||||
spin_unlock(&dreq->lock);
|
||||
|
||||
nfs_end_data_update(data->inode);
|
||||
nfs_direct_complete(dreq);
|
||||
}
|
||||
|
||||
static const struct rpc_call_ops nfs_write_direct_ops = {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user