Changeset 8160e4c0 in mainline for uspace/srv/bd/hr/raid5.c

Timestamp:

2024-11-27T13:08:27Z (8 months ago)

Author:

Miroslav Cimerman <mc@…>

Children:

40bf2c6

Parents:

bf0a791

git-author:

Miroslav Cimerman <mc@…> (2024-11-27 12:58:10)

git-committer:

Miroslav Cimerman <mc@…> (2024-11-27 13:08:27)

Message:

hr: RAID 4,5: optimize operations with xorbuf

Read block on first iteration directly to
xorbuf. This way one memset and one xor
is saved.

File:

• uspace/srv/bd/hr/raid5.c (modified) (5 diffs)

uspace/srv/bd/hr/raid5.c

@@ -329 +329 @@
 
         /* read all other extents in the stripe */
-        memset(xorbuf, 0, len);
+        bool first = true;
         for (i = 0; i < vol->dev_no; i++) {
-                if (i == bad) {
+                if (i == bad)
                         continue;
+
+                if (first) {
+                        rc = block_read_direct(vol->extents[i].svc_id, block,
+                            cnt, xorbuf);
+                        if (rc != EOK)
+                                goto end;
+
+                        first = false;
                 } else {
                         rc = block_read_direct(vol->extents[i].svc_id, block,
@@ -391 +399 @@
                  * write new parity
                  */
-                memset(xorbuf, 0, len);
+                bool first = true;
                 for (i = 1; i < vol->dev_no; i++) {
                         if (i == (size_t)bad)
                                 continue;
+                        if (first) {
+                                rc = block_read_direct(vol->extents[i].svc_id,
+                                    ba, cnt, xorbuf);
+                                if (rc != EOK)
+                                        goto end;
+
+                                first = false;
                         } else {
                                 rc = block_read_direct(vol->extents[i].svc_id,
@@ -461 +476 @@
         }
 
-        memset(xorbuf, 0, len);
+        bool first = true;
         for (i = 0; i < vol->dev_no; i++) {
                 if (i == p_extent)
                         continue;
-                if (i == extent) {
-                        xor(xorbuf, data, len);
+
+                if (first) {
+                        if (i == extent) {
+                                memcpy(xorbuf, data, len);
+                        } else {
+                                rc = block_read_direct(vol->extents[i].svc_id,
+                                    block, cnt, xorbuf);
+                                if (rc != EOK)
+                                        goto end;
+                        }
+
+                        first = false;
                 } else {
-                        rc = block_read_direct(vol->extents[i].svc_id,
-                            block, cnt, buf);
-                        if (rc != EOK)
-                                goto end;
-                        xor(xorbuf, buf, len);
+                        if (i == extent) {
+                                xor(xorbuf, data, len);
+                        } else {
+                                rc = block_read_direct(vol->extents[i].svc_id,
+                                    block, cnt, buf);
+                                if (rc != EOK)
+                                        goto end;
+
+                                xor(xorbuf, buf, len);
+                        }
                 }
         }
@@ -690 +720 @@
                         if (i == bad)
                                 continue;
-                        rc = block_read_direct(vol->extents[i].svc_id, ba, cnt,
-                            buf);
+                        if (first)
+                                rc = block_read_direct(vol->extents[i].svc_id,
+                                    ba, cnt, xorbuf);
+                        else
+                                rc = block_read_direct(vol->extents[i].svc_id,
+                                    ba, cnt, buf);
                         if (rc != EOK) {
                                 hr_raid5_handle_extent_error(vol, i, rc);
@@ -700 +734 @@
                         }
 
-                        if (first)
-                                memcpy(xorbuf, buf, cnt * vol->bsize);
+                        if (!first)
+                                xor(xorbuf, buf, cnt * vol->bsize);
                         else
-                                xor(xorbuf, buf, cnt * vol->bsize);
-
-                        first = false;
+                                first = false;
                 }