test11-pre6

Linus,

You forgot about wakeup_bdflush(1) stuff.

Here is the patch again (against test10).
===============================================================
There are several places where schedule() is called after wakeup_bdflush(1) is called. This is completely unnecessary, since wakeup_bdflush(1) already gave up the control, and when the control is returned to the calling thread who called wakeup_bdflush(1), it should just go on. Calling schedule() after wakeup_bdflush(1) will make the calling thread give up control again. This is a problem for some of those latency sensitive benchmarks (like SPEC SFS) and applications.

============

diff -ruN mm.orig/highmem.c mm.opt/highmem.c
@@ -310,8 +310,6 @@
    bh = kmem_cache_alloc(bh_cachep, SLAB_BUFFER);
    if (!bh) {
        wakeup_bdflush(1);  /* Sets task->state to TASK_RUNNING */
-       current->policy |= SCHED_YIELD;
-       schedule();
        goto repeat_bh;
    }
    /*

@@ -324,8 +322,6 @@
    page = alloc_page(GFP_BUFFER);
    if (!page) {
        wakeup_bdflush(1);  /* Sets task->state to TASK_RUNNING */
-       current->policy |= SCHED_YIELD;
-       schedule();
        goto repeat_page;
    }
    set_bh_page(bh, page, 0);

diff -ruN fs.orig/buffer.c fs.opt/buffer.c
@@ -707,11 +707,8 @@
  */
 static void refill_freelist(int size)
 {
-   if (!grow_buffers(size)) {
+   if (!grow_buffers(size))
        wakeup_bdflush(1);  /* Sets task->state to TASK_RUNNING */
-       current->policy |= SCHED_YIELD;
-       schedule();
-   }
 }
 
 void init_buffer(struct buffer_head *bh, bh_end_io_t *handler, void

*private)
==============================

Ying Chen

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From: "Ying Chen/Almaden/IBM" <[email protected]>
Date: Thu, 16 Nov 2000 19:02:25 -0800

You forgot about wakeup_bdflush(1) stuff.

What are you talking about, did you even check the patch?

Your changes are already in there.

Later,
David S. Miller
[email protected]
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