linux/drivers
Jens Axboe 9937a5e2f3 scsi: remove performance regression due to async queue run
Commit c21e6beb removed our queue request_fn re-enter
protection, and defaulted to always running the queues from
kblockd to be safe. This was a known potential slow down,
but should be safe.

Unfortunately this is causing big performance regressions for
some, so we need to improve this logic. Looking into the details
of the re-enter, the real issue is on requeue of requests.

Requeue of requests upon seeing a BUSY condition from the device
ends up re-running the queue, causing traces like this:

scsi_request_fn()
        scsi_dispatch_cmd()
                scsi_queue_insert()
                        __scsi_queue_insert()
                                scsi_run_queue()
					scsi_request_fn()
						...

potentially causing the issue we want to avoid. So special
case the requeue re-run of the queue, but improve it to offload
the entire run of local queue and starved queue from a single
workqueue callback. This is a lot better than potentially
kicking off a workqueue run for each device seen.

This also fixes the issue of the local device going into recursion,
since the above mentioned commit never moved that queue run out
of line.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-17 11:04:44 +02:00
..
accessibility
acpi Fix common misspellings 2011-03-31 11:26:23 -03:00
amba PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS 2011-04-11 22:54:42 +02:00
ata Fix common misspellings 2011-03-31 11:26:23 -03:00
atm Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
auxdisplay Fix common misspellings 2011-03-31 11:26:23 -03:00
base Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 2011-04-12 17:18:05 -07:00
block block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers 2011-04-21 21:33:05 +02:00
bluetooth Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
cdrom cdrom: always check_disk_change() on open 2011-04-29 10:17:25 +02:00
char Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus 2011-04-21 09:58:42 -07:00
clk
clocksource
connector connector: fix skb double free in cn_rx_skb() 2011-04-12 14:38:57 -07:00
cpufreq Fix common misspellings 2011-03-31 11:26:23 -03:00
cpuidle
crypto Fix common misspellings 2011-03-31 11:26:23 -03:00
dca drivers/dca/dca-core.c: use list_move() instead of list_del()/list_add() combination 2011-03-22 17:44:12 -07:00
dio
dma Merge branch 'spi/merge' of git://git.secretlab.ca/git/linux-2.6 2011-04-11 15:44:38 -07:00
edac Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
eisa
firewire Fix common misspellings 2011-03-31 11:26:23 -03:00
firmware sigma-firmware: loader for Analog Devices' SigmaStudio 2011-03-22 17:44:15 -07:00
gpio Merge branch 'spi/merge' of git://git.secretlab.ca/git/linux-2.6 2011-04-11 15:44:38 -07:00
gpu Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2011-04-21 09:57:56 -07:00
hid Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
hwmon hwmon: (pmbus) Removed unused variable from struct pmbus_data 2011-04-19 08:49:56 -07:00
hwspinlock hwspinlock: depend on OMAP4 2011-03-18 17:15:11 -07:00
i2c i2c-algo-bit: Call pre/post_xfer for bit_test 2011-04-17 10:20:19 +02:00
ide ide: unexport DISK_EVENT_MEDIA_CHANGE for ide-gd and ide-cd 2011-04-21 19:43:59 +02:00
idle
ieee802154 ieee802154: change to new flag variable 2011-03-17 14:05:34 +01:00
infiniband Fix common misspellings 2011-03-31 11:26:23 -03:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2011-04-18 13:29:03 -07:00
isdn Fix common misspellings 2011-03-31 11:26:23 -03:00
leds leds/leds-regulator.c: fix handling of already enabled regulators 2011-04-14 16:06:54 -07:00
lguest Fix common misspellings 2011-03-31 11:26:23 -03:00
macintosh Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
mca
md raid5: fix build error, sector_t usage 2011-04-21 10:00:00 -07:00
media Revert "[media] V4L: videobuf, don't use dma addr as physical" 2011-04-19 10:54:44 -07:00
memstick Fix common misspellings 2011-03-31 11:26:23 -03:00
message block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers 2011-04-21 21:33:05 +02:00
mfd mfd: Fetch cell pointer from platform_device->mfd_cell 2011-04-12 11:13:00 +02:00
misc drivers/misc/sgi-gru/grufile.c: fix the wrong members of gru_chip 2011-04-14 16:06:55 -07:00
mmc Fix common misspellings 2011-03-31 11:26:23 -03:00
mtd Merge git://git.infradead.org/mtd-2.6 2011-04-09 13:23:50 -07:00
net ip6_pol_route panic: Do not allow VLAN on loopback 2011-04-17 23:27:16 -07:00
nfc
nubus
of Fix common misspellings 2011-03-31 11:26:23 -03:00
oprofile
parisc Fix common misspellings 2011-03-31 11:26:23 -03:00
parport Fix common misspellings 2011-03-31 11:26:23 -03:00
pci Merge git://git.infradead.org/iommu-2.6 2011-04-21 09:56:35 -07:00
pcmcia ARM: pxa: convert incorrect IRQ_TO_IRQ() to irq_to_gpio() 2011-04-13 09:30:40 +08:00
platform Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86 2011-04-13 09:15:55 -07:00
pnp Fix common misspellings 2011-03-31 11:26:23 -03:00
power drivers: Final irq namespace conversion 2011-03-29 14:48:19 +02:00
pps Fix common misspellings 2011-03-31 11:26:23 -03:00
ps3 Fix common misspellings 2011-03-31 11:26:23 -03:00
rapidio RapidIO/mpc85xx: fix possible mport registration problems 2011-04-14 16:06:56 -07:00
regulator Fix common misspellings 2011-03-31 11:26:23 -03:00
rtc RTC: rtc-omap: Fix a leak of the IRQ during init failure 2011-04-18 10:39:38 +02:00
s390 block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers 2011-04-21 21:33:05 +02:00
sbus Fix common misspellings 2011-03-31 11:26:23 -03:00
scsi scsi: remove performance regression due to async queue run 2011-05-17 11:04:44 +02:00
sfi Fix common misspellings 2011-03-31 11:26:23 -03:00
sh sh: Fix irq cleanup fallout 2011-03-30 00:15:49 +02:00
sn
spi Merge branch 'spi/merge' of git://git.secretlab.ca/git/linux-2.6 2011-04-11 15:44:38 -07:00
ssb Fix common misspellings 2011-03-31 11:26:23 -03:00
staging Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86 2011-04-12 15:24:23 -07:00
target Fix common misspellings 2011-03-31 11:26:23 -03:00
tc
telephony Fix common misspellings 2011-03-31 11:26:23 -03:00
thermal
tty Merge branch 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 2011-04-07 12:48:45 -07:00
uio Fix common misspellings 2011-03-31 11:26:23 -03:00
usb Revert "USB: isp1760-hcd: move imask clear after pending work is done" 2011-04-14 13:37:07 -07:00
uwb Fix common misspellings 2011-03-31 11:26:23 -03:00
vhost
video ARM: pxafb: Fix access to nonexistent member of pxafb_info 2011-04-12 23:07:42 +08:00
virtio virtio_pci: Prevent double-free of pci regions after device hot-unplug 2011-04-21 22:57:00 +09:30
vlynq vlynq: Convert irq functions 2011-03-28 19:33:04 +02:00
w1 Fix common misspellings 2011-03-31 11:26:23 -03:00
watchdog watchdog: mpc8xxx_wdt: fix build 2011-04-07 20:20:24 +00:00
xen Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 2011-04-12 17:18:05 -07:00
zorro
Kconfig
Makefile