linux/drivers
Lars Ellenberg e4d7d6f4d3 drbd: add back some fairness to AL transactions
When batching more updates to the activity log into single transactions,
we lost the ability for new requests to force themselves into the active
set: all preparation steps became non-blocking, and if all currently
hot extents keep busy, they could starve out new incoming requests
to cold extents for quite a while.

This can only happen if your IO backend accepts more IO operations per
average DRBD replication round trip time than you have al-extents
configured.

If we have incoming requests to cold extents,
at least do one blocking update per transaction.

In an artificial worst-case workload on SSD with an asynchronous 600 ms
replication link, with al-extents = 7 (the minimum we allow), and
concurrent full resynch, without this patch, some write requests have
been observed to be starved for 40 seconds.
With this patch, application observed a worst case latency of twice the
replication round trip time.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-30 13:46:55 -06:00
..
accessibility
acpi Merge branch 'acpi-config' 2014-04-08 21:34:51 +02:00
amba ARM: SoC: driver changes 2014-04-05 15:37:40 -07:00
ata Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-04-02 16:23:38 -07:00
atm
auxdisplay
base regmap: Fix for nodev mode 2014-04-11 13:25:08 -07:00
bcma
block drbd: add back some fairness to AL transactions 2014-04-30 13:46:55 -06:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
bus ARM: SoC: driver changes 2014-04-05 15:37:40 -07:00
cdrom gdrom: missed conversion from req->buffer 2014-04-16 14:15:24 -06:00
char Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
clk == Changes to existing drivers == 2014-04-07 10:24:18 -07:00
clocksource CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
connector Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
cpufreq Merge branch 'pm-cpufreq' 2014-04-08 13:28:02 +02:00
cpuidle Merge branch 'pm-cpuidle' 2014-04-08 13:27:40 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2014-04-03 09:28:16 -07:00
dca
devfreq
dio
dma Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-04-10 08:55:08 -07:00
edac Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-04-04 09:50:07 -07:00
eisa
extcon
firewire
firmware Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-11 11:58:33 -07:00
fmc
gpio == Changes to existing drivers == 2014-04-07 10:24:18 -07:00
gpu Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-04-08 09:52:16 -07:00
hid Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-04-04 09:50:07 -07:00
hsi
hv Char/Misc driver patches for 3.15-rc1 2014-04-01 16:13:21 -07:00
hwmon Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-04-09 08:35:31 -07:00
hwspinlock
i2c Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-04-09 08:45:40 -07:00
ide block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
idle Merge branch 'pm-cpuidle' 2014-04-08 13:27:40 +02:00
iio == Changes to existing drivers == 2014-04-07 10:24:18 -07:00
infiniband Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-04-12 16:51:08 -07:00
input pwm: Changes for v3.15-rc1 2014-04-05 18:32:31 -07:00
iommu IOMMU Upates for Linux v3.15 2014-04-05 18:46:26 -07:00
ipack
irqchip ARM: SoC: driver changes 2014-04-05 15:37:40 -07:00
isdn isdnloop: several buffer overflows 2014-04-08 12:41:13 -04:00
leds Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds 2014-04-10 09:06:10 -07:00
lguest drivers/lguest/page_tables.c: rename do_set_pte() 2014-04-07 16:35:52 -07:00
macintosh
mailbox
mcb
md block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
media [media] gpsca: remove the risk of a division by zero 2014-04-08 11:01:12 -03:00
memory
memstick
message PCI changes for the v3.15 merge window: 2014-04-01 15:14:04 -07:00
mfd MMC highlights for 3.15: 2014-04-09 08:39:39 -07:00
misc drivers/misc/sgi-gru/grukdump.c: cleanup gru_dump_context() a little 2014-04-07 16:36:09 -07:00
mmc MMC highlights for 3.15: 2014-04-09 08:39:39 -07:00
mtd block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
nfc
ntb ntb: Use pci_enable_msix_range() instead of pci_enable_msix() 2014-04-07 10:59:20 -07:00
nubus
of MTD updates for 3.15: 2014-04-07 10:17:30 -07:00
oprofile
parisc
parport
pci Nothing major: the stricter permissions checking for sysfs broke 2014-04-06 09:38:07 -07:00
pcmcia PCI changes for the v3.15 merge window: 2014-04-01 15:14:04 -07:00
phy ARM: SoC: driver changes 2014-04-05 15:37:40 -07:00
pinctrl This is the bulk of GPIO changes for v3.15: 2014-04-03 16:44:15 -07:00
platform alienware-wmi: cover some scenarios where memory allocations would fail 2014-04-10 12:11:56 -04:00
pnp More ACPI and power management updates for 3.15-rc1 2014-04-02 14:10:21 -07:00
power
powercap CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
pps
ps3
ptp net: ptp: move PTP classifier in its own file 2014-04-01 16:43:18 -04:00
pwm pwm: Changes for v3.15-rc1 2014-04-05 18:32:31 -07:00
rapidio rapidio: rework device hierarchy and introduce mport class of devices 2014-04-07 16:36:07 -07:00
regulator regulator: Fixes for v3.15 2014-04-11 13:30:05 -07:00
remoteproc
reset
rpmsg
rtc ARM: SoC: driver changes 2014-04-05 15:37:40 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-04-08 12:02:28 -07:00
sbus jsflash: missed conversion from rq->buffer to bio_data(rq->bio) 2014-04-16 14:15:25 -06:00
scsi block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
sfi
sh ARM: SoC: sh driver changes 2014-04-05 15:38:41 -07:00
sn
spi spi: Fixes for v3.15 2014-04-11 13:35:49 -07:00
spmi
ssb
staging Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
target Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
tc
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2014-04-10 09:15:46 -07:00
tty Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
uio
usb Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-04-12 16:51:08 -07:00
uwb
vfio VFIO updates for v3.15 include: 2014-04-03 14:05:02 -07:00
vhost Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-04-12 16:51:08 -07:00
video - Call put_device() instead of kfree() - core 2014-04-10 08:52:35 -07:00
virt
virtio
vlynq
vme
w1
watchdog CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
xen Fix arm build of drivers/xen/events/ 2014-04-07 17:50:18 -07:00
zorro
Kconfig
Makefile