2.4.13-ac8

 fs

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla/fs/iobuf.c linux.ac/fs/iobuf.c
--- linux.vanilla/fs/iobuf.c   Fri Apr 27 22:23:25 2001
+++ linux.ac/fs/iobuf.c   Wed Oct 10 01:48:22 2001
@@ -4,12 +4,19 @@
  * Keep track of the general-purpose IO-buffer structures used to track
  * abstract kernel-space io buffers.
  * 
+ * 07/20/01 Rohit Seth <rohit.seth@intel.com> Made the iobuf come from
+ * kiobuf cache instead of vmalloc (that is a killer for most of archs.)  These
+ * changes are specifically targeted for increasing raw IO performance.
+ * Introducing the new *_sz functions that take the number of bhs actually 
+ * required by kiovec.  
  */
 
 #include <linux/iobuf.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
+static   kmem_cache_t   *kiobuf_cachep;
+
 void end_kio_request(struct kiobuf *kiobuf, int uptodate)
 {
    if ((!uptodate) && !kiobuf->errno)
@@ -22,19 +29,32 @@
    }
 }
 
+void __init kiobuf_setup(void)
+{
+    kiobuf_cachep =  kmem_cache_create("kiobuf",
+                       sizeof(struct kiobuf),
+                       0,
+                       SLAB_HWCACHE_ALIGN, NULL, NULL);
+    if(!kiobuf_cachep)
+        panic("Cannot create kernel iobuf cache\n");
+}
+
 static void kiobuf_init(struct kiobuf *iobuf)
 {
-   memset(iobuf, 0, sizeof(*iobuf));
    init_waitqueue_head(&iobuf->wait_queue);
    iobuf->array_len = KIO_STATIC_PAGES;
    iobuf->maplist   = iobuf->map_array;
+   iobuf->nr_pages = 0;
+   iobuf->locked = 0;
+   iobuf->io_count.counter = 0;
+   iobuf->end_io = NULL;
 }
 
-int alloc_kiobuf_bhs(struct kiobuf * kiobuf)
+int alloc_kiobuf_bhs_sz(struct kiobuf * kiobuf, int sz)
 {
    int i;
 
-   for (i = 0; i < KIO_MAX_SECTORS; i++)
+   for (i = 0; i < sz; i++)
       if (!(kiobuf->bh[i] = kmem_cache_alloc(bh_cachep, SLAB_KERNEL))) {
          while (i--) {
             kmem_cache_free(bh_cachep, kiobuf->bh[i]);
@@ -45,40 +65,42 @@
    return 0;
 }
 
-void free_kiobuf_bhs(struct kiobuf * kiobuf)
+void free_kiobuf_bhs_sz(struct kiobuf * kiobuf, int sz)
 {
    int i;
 
-   for (i = 0; i < KIO_MAX_SECTORS; i++) {
+   for (i = 0; i < sz; i++) {
       kmem_cache_free(bh_cachep, kiobuf->bh[i]);
       kiobuf->bh[i] = NULL;
    }
 }
 
-int alloc_kiovec(int nr, struct kiobuf **bufp)
+int alloc_kiovec_sz(int nr, struct kiobuf **bufp, int *szp)
 {
    int i;
    struct kiobuf *iobuf;
+   int   *tszp = szp;
    
    for (i = 0; i < nr; i++) {
-      iobuf = vmalloc(sizeof(struct kiobuf));
+      iobuf = kmem_cache_alloc(kiobuf_cachep, SLAB_KERNEL);
       if (!iobuf) {
-         free_kiovec(i, bufp);
+         free_kiovec_sz(i, bufp, szp);
          return -ENOMEM;
       }
       kiobuf_init(iobuf);
-       if (alloc_kiobuf_bhs(iobuf)) {
-         vfree(iobuf);
-          free_kiovec(i, bufp);
+       if (alloc_kiobuf_bhs_sz(iobuf,*tszp)) {
+         kmem_cache_free(kiobuf_cachep, iobuf);
+          free_kiovec_sz(i, bufp, szp);
           return -ENOMEM;
        }
+      tszp++;
       bufp[i] = iobuf;
    }
    
    return 0;
 }
 
-void free_kiovec(int nr, struct kiobuf **bufp) 
+void free_kiovec_sz(int nr, struct kiobuf **bufp, int *szp) 
 {
    int i;
    struct kiobuf *iobuf;
@@ -89,8 +111,9 @@
          unlock_kiovec(1, &iobuf);
       if (iobuf->array_len > KIO_STATIC_PAGES)
          kfree (iobuf->maplist);
-      free_kiobuf_bhs(iobuf);
-      vfree(bufp[i]);
+      free_kiobuf_bhs_sz(iobuf,*szp);
+      kmem_cache_free(kiobuf_cachep, bufp[i]);
+      szp++;
    }
 }
 
@@ -122,7 +145,6 @@
    return 0;
 }
 
-
 void kiobuf_wait_for_io(struct kiobuf *kiobuf)
 {
    struct task_struct *tsk = current;
@@ -143,6 +165,5 @@
    tsk->state = TASK_RUNNING;
    remove_wait_queue(&kiobuf->wait_queue, &wait);
 }
-