| Message ID | 20250211100053.9485-1-sprasad@microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | cifs: pick channels for individual subrequests | expand |
tentatively merged to cifs-2.6.git for-next pending more testing/review On Tue, Feb 11, 2025 at 4:01 AM <nspmangalore@gmail.com> wrote: > > From: Shyam Prasad N <sprasad@microsoft.com> > > The netfs library could break down a read request into > multiple subrequests. When multichannel is used, there is > potential to improve performance when each of these > subrequests pick a different channel. > > Today we call cifs_pick_channel when the main read request > is initialized in cifs_init_request. This change moves this to > cifs_prepare_read, which is the right place to pick channel since > it gets called for each subrequest. > > Interestingly cifs_prepare_write already does channel selection > for individual subreq, but looks like it was missed for read. > This is especially important when multichannel is used with > increased rasize. > > In my test setup, with rasize set to 8MB, a sequential read > of large file was taking 11.5s without this change. With the > change, it completed in 9s. The difference is even more signigicant > with bigger rasize. > > Cc: <stable@vger.kernel.org> > Cc: David Howells <dhowells@redhat.com> > Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> > --- > fs/smb/client/cifsglob.h | 1 - > fs/smb/client/file.c | 7 ++++--- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h > index a68434ad744a..243e4881528c 100644 > --- a/fs/smb/client/cifsglob.h > +++ b/fs/smb/client/cifsglob.h > @@ -1508,7 +1508,6 @@ struct cifs_io_parms { > struct cifs_io_request { > struct netfs_io_request rreq; > struct cifsFileInfo *cfile; > - struct TCP_Server_Info *server; > pid_t pid; > }; > > diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c > index 79de2f2f9c41..8582cf61242c 100644 > --- a/fs/smb/client/file.c > +++ b/fs/smb/client/file.c > @@ -147,7 +147,7 @@ static int cifs_prepare_read(struct netfs_io_subrequest *subreq) > struct netfs_io_request *rreq = subreq->rreq; > struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq); > struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq); > - struct TCP_Server_Info *server = req->server; > + struct TCP_Server_Info *server; > struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb); > size_t size; > int rc = 0; > @@ -156,6 +156,8 @@ static int cifs_prepare_read(struct netfs_io_subrequest *subreq) > rdata->xid = get_xid(); > rdata->have_xid = true; > } > + > + server = cifs_pick_channel(tlink_tcon(req->cfile->tlink)->ses); > rdata->server = server; > > if (cifs_sb->ctx->rsize == 0) > @@ -198,7 +200,7 @@ static void cifs_issue_read(struct netfs_io_subrequest *subreq) > struct netfs_io_request *rreq = subreq->rreq; > struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq); > struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq); > - struct TCP_Server_Info *server = req->server; > + struct TCP_Server_Info *server = rdata->server; > int rc = 0; > > cifs_dbg(FYI, "%s: op=%08x[%x] mapping=%p len=%zu/%zu\n", > @@ -266,7 +268,6 @@ static int cifs_init_request(struct netfs_io_request *rreq, struct file *file) > open_file = file->private_data; > rreq->netfs_priv = file->private_data; > req->cfile = cifsFileInfo_get(open_file); > - req->server = cifs_pick_channel(tlink_tcon(req->cfile->tlink)->ses); > if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) > req->pid = req->cfile->pid; > } else if (rreq->origin != NETFS_WRITEBACK) { > -- > 2.43.0 >
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index a68434ad744a..243e4881528c 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -1508,7 +1508,6 @@ struct cifs_io_parms { struct cifs_io_request { struct netfs_io_request rreq; struct cifsFileInfo *cfile; - struct TCP_Server_Info *server; pid_t pid; }; diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 79de2f2f9c41..8582cf61242c 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -147,7 +147,7 @@ static int cifs_prepare_read(struct netfs_io_subrequest *subreq) struct netfs_io_request *rreq = subreq->rreq; struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq); struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq); - struct TCP_Server_Info *server = req->server; + struct TCP_Server_Info *server; struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb); size_t size; int rc = 0; @@ -156,6 +156,8 @@ static int cifs_prepare_read(struct netfs_io_subrequest *subreq) rdata->xid = get_xid(); rdata->have_xid = true; } + + server = cifs_pick_channel(tlink_tcon(req->cfile->tlink)->ses); rdata->server = server; if (cifs_sb->ctx->rsize == 0) @@ -198,7 +200,7 @@ static void cifs_issue_read(struct netfs_io_subrequest *subreq) struct netfs_io_request *rreq = subreq->rreq; struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq); struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq); - struct TCP_Server_Info *server = req->server; + struct TCP_Server_Info *server = rdata->server; int rc = 0; cifs_dbg(FYI, "%s: op=%08x[%x] mapping=%p len=%zu/%zu\n", @@ -266,7 +268,6 @@ static int cifs_init_request(struct netfs_io_request *rreq, struct file *file) open_file = file->private_data; rreq->netfs_priv = file->private_data; req->cfile = cifsFileInfo_get(open_file); - req->server = cifs_pick_channel(tlink_tcon(req->cfile->tlink)->ses); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) req->pid = req->cfile->pid; } else if (rreq->origin != NETFS_WRITEBACK) {