[PATCH] better sizing of queue_nr_requests

Patch from 2.4 sets the maximum size of the queue in a more sensible manner

diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index f34dde5dcfcbcd8344055fe4300c3eca2b7911ae..5396cba9b3873ff1c92a8e5b634b6778989b0611 100644 (file)
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -1924,9 +1924,11 @@ int __init blk_dev_init(void)
         * Free request slots per queue.
         * (Half for reads, half for writes)
         */
-       queue_nr_requests = 64;
-       if (total_ram > MB(32))
-               queue_nr_requests = 256;
+       queue_nr_requests = (total_ram >> 8) & ~15;     /* One per quarter-megabyte */
+       if (queue_nr_requests < 32)
+               queue_nr_requests = 32;
+       if (queue_nr_requests > 512)
+               queue_nr_requests = 512;
 
        /*
         * Batch frees according to queue length