On Fri, 3 Aug 2001, Ben LaHaise wrote:
> See, after applying this patch, it no longer deadlocks on io. The
> jerky interactive performance still exists,
Would something like this help ?
(yes, there's a small SMP race, but since the system survives
the starvation bug today that isn't critical)
--- ./ll_rw_blk.c.batch Sat Aug 4 00:30:55 2001
+++ ./ll_rw_blk.c Sat Aug 4 00:33:48 2001
@@ -1031,15 +1031,19 @@
for (i = 0; i < nr; i++) {
struct buffer_head *bh = bhs[i];
+ static int queued_sector_waiters;
/*
* don't lock any more buffers if we are above the high
* water mark. instead start I/O on the queued stuff.
*/
- if (atomic_read(&queued_sectors) >= high_queued_sectors) {
+ if (atomic_read(&queued_sectors) >= high_queued_sectors
+ || queued_sector_waiters) {
run_task_queue(&tq_disk);
+ queued_sector_waiters = 1;
wait_event(blk_buffers_wait,
atomic_read(&queued_sectors) < low_queued_sectors);
+ queued_sector_waiters = 0;
}
/* Only one thread can actually submit the I/O. */
Rik
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This archive was generated by hypermail 2b29 : Tue Aug 07 2001 - 21:00:31 EST