| Message ID | 20180530194807.31657-10-longli@linuxonhyperv.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 5/30/2018 3:48 PM, Long Li wrote: > From: Long Li <longli@microsoft.com> > > RDMA recv function needs to place data to the correct place starting at > page offset. > > Signed-off-by: Long Li <longli@microsoft.com> > --- > fs/cifs/smbdirect.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c > index 6141e3c..ba53c52 100644 > --- a/fs/cifs/smbdirect.c > +++ b/fs/cifs/smbdirect.c > @@ -2004,10 +2004,12 @@ static int smbd_recv_buf(struct smbd_connection *info, char *buf, > * return value: actual data read > */ > static int smbd_recv_page(struct smbd_connection *info, > - struct page *page, unsigned int to_read) > + struct page *page, unsigned int page_offset, > + unsigned int to_read) > { > int ret; > char *to_address; > + void *page_address; > > /* make sure we have the page ready for read */ > ret = wait_event_interruptible( > @@ -2015,16 +2017,17 @@ static int smbd_recv_page(struct smbd_connection *info, > info->reassembly_data_length >= to_read || > info->transport_status != SMBD_CONNECTED); > if (ret) > - return 0; > + return ret; > > /* now we can read from reassembly queue and not sleep */ > - to_address = kmap_atomic(page); > + page_address = kmap_atomic(page); > + to_address = (char *) page_address + page_offset; > > log_read(INFO, "reading from page=%p address=%p to_read=%d\n", > page, to_address, to_read); > > ret = smbd_recv_buf(info, to_address, to_read); > - kunmap_atomic(to_address); > + kunmap_atomic(page_address); Is "page" truly not mapped? This kmap/kunmap for each received 4KB is very expensive. Is there not a way to keep a kva for the reassembly queue segments? > > return ret; > } > @@ -2038,7 +2041,7 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg) > { > char *buf; > struct page *page; > - unsigned int to_read; > + unsigned int to_read, page_offset; > int rc; > > info->smbd_recv_pending++; > @@ -2052,15 +2055,16 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg) > > case READ | ITER_BVEC: > page = msg->msg_iter.bvec->bv_page; > + page_offset = msg->msg_iter.bvec->bv_offset; > to_read = msg->msg_iter.bvec->bv_len; > - rc = smbd_recv_page(info, page, to_read); > + rc = smbd_recv_page(info, page, page_offset, to_read); > break; > > default: > /* It's a bug in upper layer to get there */ > cifs_dbg(VFS, "CIFS: invalid msg type %d\n", > msg->msg_iter.type); > - rc = -EIO; > + rc = -EINVAL; > } > > info->smbd_recv_pending--; > -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> Subject: Re: [Patch v2 09/15] CIFS: SMBD: Support page offset in RDMA recv > > On 5/30/2018 3:48 PM, Long Li wrote: > > From: Long Li <longli@microsoft.com> > > > > RDMA recv function needs to place data to the correct place starting > > at page offset. > > > > Signed-off-by: Long Li <longli@microsoft.com> > > --- > > fs/cifs/smbdirect.c | 18 +++++++++++------- > > 1 file changed, 11 insertions(+), 7 deletions(-) > > > > diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index > > 6141e3c..ba53c52 100644 > > --- a/fs/cifs/smbdirect.c > > +++ b/fs/cifs/smbdirect.c > > @@ -2004,10 +2004,12 @@ static int smbd_recv_buf(struct > smbd_connection *info, char *buf, > > * return value: actual data read > > */ > > static int smbd_recv_page(struct smbd_connection *info, > > - struct page *page, unsigned int to_read) > > + struct page *page, unsigned int page_offset, > > + unsigned int to_read) > > { > > int ret; > > char *to_address; > > + void *page_address; > > > > /* make sure we have the page ready for read */ > > ret = wait_event_interruptible( > > @@ -2015,16 +2017,17 @@ static int smbd_recv_page(struct > smbd_connection *info, > > info->reassembly_data_length >= to_read || > > info->transport_status != SMBD_CONNECTED); > > if (ret) > > - return 0; > > + return ret; > > > > /* now we can read from reassembly queue and not sleep */ > > - to_address = kmap_atomic(page); > > + page_address = kmap_atomic(page); > > + to_address = (char *) page_address + page_offset; > > > > log_read(INFO, "reading from page=%p address=%p to_read=%d\n", > > page, to_address, to_read); > > > > ret = smbd_recv_buf(info, to_address, to_read); > > - kunmap_atomic(to_address); > > + kunmap_atomic(page_address); > > Is "page" truly not mapped? This kmap/kunmap for each received 4KB is very > expensive. Is there not a way to keep a kva for the reassembly queue > segments? I will find a way to not map those upper layer pages when doing RDMA receive. The reason for doing this is to use a common layer (that will greatly simplifies the code) for transport. It's probably a waste of time when only pages are involved, and not need to be mapped. I will address those in a separate patch. > > > > > return ret; > > } > > @@ -2038,7 +2041,7 @@ int smbd_recv(struct smbd_connection *info, > struct msghdr *msg) > > { > > char *buf; > > struct page *page; > > - unsigned int to_read; > > + unsigned int to_read, page_offset; > > int rc; > > > > info->smbd_recv_pending++; > > @@ -2052,15 +2055,16 @@ int smbd_recv(struct smbd_connection *info, > > struct msghdr *msg) > > > > case READ | ITER_BVEC: > > page = msg->msg_iter.bvec->bv_page; > > + page_offset = msg->msg_iter.bvec->bv_offset; > > to_read = msg->msg_iter.bvec->bv_len; > > - rc = smbd_recv_page(info, page, to_read); > > + rc = smbd_recv_page(info, page, page_offset, to_read); > > break; > > > > default: > > /* It's a bug in upper layer to get there */ > > cifs_dbg(VFS, "CIFS: invalid msg type %d\n", > > msg->msg_iter.type); > > - rc = -EIO; > > + rc = -EINVAL; > > } > > > > info->smbd_recv_pending--; > >
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 6141e3c..ba53c52 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -2004,10 +2004,12 @@ static int smbd_recv_buf(struct smbd_connection *info, char *buf, * return value: actual data read */ static int smbd_recv_page(struct smbd_connection *info, - struct page *page, unsigned int to_read) + struct page *page, unsigned int page_offset, + unsigned int to_read) { int ret; char *to_address; + void *page_address; /* make sure we have the page ready for read */ ret = wait_event_interruptible( @@ -2015,16 +2017,17 @@ static int smbd_recv_page(struct smbd_connection *info, info->reassembly_data_length >= to_read || info->transport_status != SMBD_CONNECTED); if (ret) - return 0; + return ret; /* now we can read from reassembly queue and not sleep */ - to_address = kmap_atomic(page); + page_address = kmap_atomic(page); + to_address = (char *) page_address + page_offset; log_read(INFO, "reading from page=%p address=%p to_read=%d\n", page, to_address, to_read); ret = smbd_recv_buf(info, to_address, to_read); - kunmap_atomic(to_address); + kunmap_atomic(page_address); return ret; } @@ -2038,7 +2041,7 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg) { char *buf; struct page *page; - unsigned int to_read; + unsigned int to_read, page_offset; int rc; info->smbd_recv_pending++; @@ -2052,15 +2055,16 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg) case READ | ITER_BVEC: page = msg->msg_iter.bvec->bv_page; + page_offset = msg->msg_iter.bvec->bv_offset; to_read = msg->msg_iter.bvec->bv_len; - rc = smbd_recv_page(info, page, to_read); + rc = smbd_recv_page(info, page, page_offset, to_read); break; default: /* It's a bug in upper layer to get there */ cifs_dbg(VFS, "CIFS: invalid msg type %d\n", msg->msg_iter.type); - rc = -EIO; + rc = -EINVAL; } info->smbd_recv_pending--;