cifs: ask for more credit on async read/write code paths

When doing a large read or write workload we only
very gradually increase the number of credits
which can cause problems with parallelizing large i/o
(I/O ramps up more slowly than it should for large
read/write workloads) especially with multichannel
when the number of credits on the secondary channels
starts out low (e.g. less than about 130) or when
recovering after server throttled back the number
of credit.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 4bbb6126b14d6e9a3703129a5616dff47611e11f..2199a9bfae8f79b60b35f53e9ea3dc696beb4665 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -4041,8 +4041,7 @@ smb2_async_readv(struct cifs_readdata *rdata)
        if (rdata->credits.value > 0) {
                shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
                                                SMB2_MAX_BUFFER_SIZE));
-               shdr->CreditRequest =
-                       cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
+               shdr->CreditRequest = cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 8);
 
                rc = adjust_credits(server, &rdata->credits, rdata->bytes);
                if (rc)
@@ -4348,8 +4347,7 @@ smb2_async_writev(struct cifs_writedata *wdata,
        if (wdata->credits.value > 0) {
                shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
                                                    SMB2_MAX_BUFFER_SIZE));
-               shdr->CreditRequest =
-                       cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
+               shdr->CreditRequest = cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 8);
 
                rc = adjust_credits(server, &wdata->credits, wdata->bytes);
                if (rc)