linux/drivers/block
Paul Clements 48f15b93b2 NBD: make nbd default to deadline I/O scheduler
NBD doesn't work well with CFQ (or AS) schedulers, so let's default to
something else.

The two problems I have experienced with nbd and cfq are:

1) nbd hangs with cfq on RHEL 5 (2.6.18) -- this may well have been
   fixed

   There's a similar debian bug that has been filed as well:

   http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=447638

   There have been posts to nbd-general mailing list about problems with
   cfq and nbd also.

2) nbd performs about 10% better (the last time I tested) with deadline
   vs.  cfq (the overhead of cfq doesn't provide much advantage to nbd [not
   being a real disk], and you end up going through the I/O scheduler on
   the nbd server anyway, so it makes sense that deadline is better with
   nbd)

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 17:12:15 -08:00
..
aoe Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2008-02-08 09:42:46 -08:00
paride fix ! versus & precedence in various places 2008-02-06 10:40:59 -08:00
amiflop.c [BLOCK] Get rid of request_queue_t typedef 2007-07-24 09:28:11 +02:00
ataflop.c Atari floppy: Rename disk_type to atari_disk_type 2008-02-06 10:41:10 -08:00
brd.c rd: support XIP 2008-02-08 09:22:30 -08:00
cciss_cmd.h [PATCH] cciss: add support for 1024 logical volumes 2006-12-07 08:39:30 -08:00
cciss_scsi.c drivers/block/: Spelling fixes 2008-02-03 17:09:38 +02:00
cciss_scsi.h cciss: update copyright notices 2007-10-29 11:33:05 +01:00
cciss.c cciss: use upper_32_bits() macro to eliminate warnings 2008-02-06 10:41:03 -08:00
cciss.h [PATCH] cciss: add support for 1024 logical volumes 2006-12-07 08:39:30 -08:00
cpqarray.c blk_end_request: changing cpqarray (take 4) 2008-01-28 10:37:00 +01:00
cpqarray.h
cryptoloop.c SG: Change sg_set_page() to take length and offset argument 2007-10-24 11:20:47 +02:00
DAC960.c blk_end_request: changing DAC960 (take 4) 2008-01-28 10:36:04 +01:00
DAC960.h Fix DAC960 driver on machines which don't support 64-bit DMA 2007-09-11 17:21:19 -07:00
floppy.c blk_end_request: changing floppy (take 4) 2008-01-28 10:36:21 +01:00
ida_cmd.h
ida_ioctl.h
Kconfig rd: support XIP 2008-02-08 09:22:30 -08:00
loop.c Allow auto-destruction of loop devices 2008-02-06 10:41:01 -08:00
Makefile rewrite rd 2008-02-08 09:22:30 -08:00
nbd.c NBD: make nbd default to deadline I/O scheduler 2008-02-23 17:12:15 -08:00
pktcdvd.c fix ! versus & precedence in various places 2008-02-06 10:40:59 -08:00
ps2esdi.c [BLOCK] Get rid of request_queue_t typedef 2007-07-24 09:28:11 +02:00
ps3disk.c blk_end_request: changing ps3disk (take 4) 2008-01-28 10:36:38 +01:00
smart1,2.h
sunvdc.c block/sunvdc.c:print_version() must be __devinit 2008-02-01 09:26:32 +01:00
swim3.c Fix compile of swim3 as module 2008-02-14 20:58:04 -08:00
sx8.c blk_end_request: changing sx8 (take 4) 2008-01-28 10:36:42 +01:00
ub.c ub: fix up the conversion to sg_init_table() 2008-02-09 11:08:33 -08:00
umem.c Cleanup umem driver: fix most checkpatch warnings, conform to kernel 2007-12-18 08:29:28 +01:00
umem.h drivers/block/umem: trim trailing whitespace 2007-10-10 09:25:59 +02:00
viodasd.c blk_end_request: changing viodasd (take 4) 2008-01-28 10:36:44 +01:00
virtio_blk.c virtio_blk: implement naming for vda-vdz,vdaa-vdzz,vdaaa-vdzzz 2008-02-04 23:50:11 +11:00
xd.c [BLOCK] Get rid of request_queue_t typedef 2007-07-24 09:28:11 +02:00
xd.h [BLOCK] Get rid of request_queue_t typedef 2007-07-24 09:28:11 +02:00
xen-blkfront.c xen: Implement getgeo for Xen virtual block device. 2008-02-21 16:19:13 -08:00
xsysace.c [POWERPC] Xilinx: Update compatible to use values generated by BSP generator. 2008-02-06 10:23:21 -07:00
z2ram.c [BLOCK] Get rid of request_queue_t typedef 2007-07-24 09:28:11 +02:00