- Data digest SMP scalability imcreased

 - Iscsi_dump_char() made thread safe

git-svn-id: https://scst.svn.sourceforge.net/svnroot/scst/trunk@841 d57e44dd-8a1f-0410-8b47-8ef2f437770f

diff --git a/iscsi-scst/kernel/config.c b/iscsi-scst/kernel/config.c
index 537b21e..caefea8 100644 (file)
--- a/iscsi-scst/kernel/config.c
+++ b/iscsi-scst/kernel/config.c
@@ -482,10 +482,9 @@ const struct file_operations ctr_fops = {
 };
 
 #ifdef CONFIG_SCST_DEBUG
-static void iscsi_dump_char(int ch)
+static void iscsi_dump_char(int ch, unsigned char *text, int *pos)
 {
-       static unsigned char text[16];
-       static int i;
+       int i = *pos;
 
        if (ch < 0) {
                while ((i % 16) != 0) {
@@ -498,7 +497,7 @@ static void iscsi_dump_char(int ch)
                                printk(KERN_CONT " |");
                }
                i = 0;
-               return;
+               goto out;
        }
 
        text[i] = (ch < 0x20 || (ch >= 0x80 && ch <= 0xa0)) ? ' ' : ch;
@@ -509,10 +508,17 @@ static void iscsi_dump_char(int ch)
                i = 0;
        } else if ((i % 4) == 0)
                printk(KERN_CONT " |");
+
+out:
+       *pos = i;
+       return;
 }
 
 void iscsi_dump_pdu(struct iscsi_pdu *pdu)
 {
+       unsigned char text[16];
+       int pos = 0;
+
        if (trace_flag & TRACE_D_DUMP_PDU) {
                unsigned char *buf;
                int i;
@@ -520,14 +526,14 @@ void iscsi_dump_pdu(struct iscsi_pdu *pdu)
                buf = (void *)&pdu->bhs;
                printk(KERN_DEBUG "BHS: (%p,%zd)\n", buf, sizeof(pdu->bhs));
                for (i = 0; i < sizeof(pdu->bhs); i++)
-                       iscsi_dump_char(*buf++);
-               iscsi_dump_char(-1);
+                       iscsi_dump_char(*buf++, text, &pos);
+               iscsi_dump_char(-1, text, &pos);
 
                buf = (void *)pdu->ahs;
                printk(KERN_DEBUG "AHS: (%p,%d)\n", buf, pdu->ahssize);
                for (i = 0; i < pdu->ahssize; i++)
-                       iscsi_dump_char(*buf++);
-               iscsi_dump_char(-1);
+                       iscsi_dump_char(*buf++, text, &pos);
+               iscsi_dump_char(-1, text, &pos);
 
                printk(KERN_DEBUG "Data: (%d)\n", pdu->datasize);
        }

diff --git a/iscsi-scst/kernel/nthread.c b/iscsi-scst/kernel/nthread.c
index e3e459f..da557ec 100644 (file)
--- a/iscsi-scst/kernel/nthread.c
+++ b/iscsi-scst/kernel/nthread.c
@@ -824,8 +824,12 @@ static int recv(struct iscsi_conn *conn)
                        break;
        case RX_CHECK_DDIGEST:
                conn->read_state = RX_END;
-               if (cmnd->pdu.datasize <= 256*1024) {
-                       /* It's cache hot, so let's compute it inline */
+               if (cmnd->pdu.datasize <= 16*1024) {
+                       /*
+                        * It's cache hot, so let's compute it inline. The
+                        * choice here about what will expose more latency:
+                        * possible cache misses or the digest calculation.
+                        */
                        TRACE_DBG("cmnd %p, opcode %x: checking RX "
                                "ddigest inline", cmnd, cmnd_opcode(cmnd));
                        cmnd->ddigest_checked = 1;