On Saturday 22 March 2003 04:05 am, Andrew Morton wrote:
> OK, thanks. So with 48 disks you've lost five megabytes to blkdev_requests
> and deadline_drq objects. With 4000 disks, you're toast. That's enough
> request structures to put 200 gigabytes of memory under I/O ;)
>
> We need to make the request structures dymanically allocated for other
> reasons (which I cannot immediately remember) but it didn't happen. I
> guess we have some motivation now.
Here is the list of slab caches which consumed more than 1 MB
in the process of inserting 4000 disks.
#insmod scsi_debug.ko add_host=4 num_devs=1000
deadline_drq before:1280 after:1025420 diff:1024140 size:64 incr:65544960
blkdev_requests before:1280 after:1025400 diff:1024120 size:156 incr:159762720
* deadline_drq, blkdev_requests consumed almost 80 MB. We need to fix this.
inode_cache before:700 after:140770 diff:140070 size:364 incr:50985480
dentry_cache before:4977 after:145061 diff:140084 size:172 incr:24094448
* inode cache increased by 50 MB, dentry cache 24 MB.
It looks like we cached 140,000 inodes. I wonder why ?
size-8192 before:8 after:4010 diff:4002 size:8192 incr:32784384
* 32 MB is for 4 hosts ram disk for scsi_debug (4*8MB)
size-2048 before:112 after:4102 diff:3990 size:2060 incr:8219400
size-512 before:87 after:8085 diff:7998 size:524 incr:4190952
size-192 before:907 after:16910 diff:16003 size:204 incr:3264612
size-64 before:459 after:76500 diff:76041 size:76 incr:5779116
size-32 before:523 after:24528 diff:24005 size:44 incr:1056220
* 30MB for all other structures. I need to look closely on what these are..
Thanks,
Badari
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Mar 31 2003 - 22:00:17 EST