Theory confirmed, due to the fix the real "capable" max kb is set, that
lets the block device layer merge and hold back requests. Only to later
be split by the raid controller.
Following the IRC discussion using that as a tuning to "fix" is ok.
Closing as as it turned out not to be a bug.
The kernel has the proper tunable already (the one we used), but having
a knob in the HW controller might be worth to avoid everybody finding
that the hard way.
** Changed in: linux (Ubuntu)
Status: Confirmed => Invalid
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1668557
Title:
Write performance regression severely affecting hpsa controllers
Status in linux package in Ubuntu:
Invalid
Bug description:
Upgrading our HP(E) servers to xenial we have discovered a severe
performance regression affecting write performance on Smart Array RAID
logical drives.
Firmware is up to date with latest HPE SPP release at the time of
testing.
This performance regression has been verified on multiple sites with
different HPE systems and OS:s, downgrading kernel brings back the
expected performance.
We are NOT seeing this on Dell hardware with H730P (LSI based)
controllers, using the same OS installs.
Our test system setup:
Ubuntu 16.04.2 LTS
Server: HP(E) DL380e, 36 G RAM, 1x E5-2420 CPU
RAID Controller: Smart Array P420 2GB FBWC
RAID setup: 24x 500G SAS HDDs in RAID50 with 2 parity groups.
File system: xfs
We are also seeing this issue on setups using DL380e with P430
controller and 14 HDDs in RAID6, but those systems are not available
for testing.
Fast/normal (previous) bulk IO performance is approx 1600-1800 MB/s
sustained read and write using a simple dd bs=256k based test.
Slow/performance regression reduces the write performance to approx
500-600 MB/s sustained using the same tests and filesystem.
We have tested using the following OS installs and kernels:
Precise:
All tested Ubuntu kernels are fast.
Trusty:
trusty 3.13.0.110.118 fast
utopic 3.16.0.77.68 fast
vivid 3.19.0.80.62 slow
xenial 4.4.0.64.50 slow
Xenial:
xenial 4.4.0.64.68 slow
hwe 4.8.0.39.10 slow
mainline 3.12.64-031264.201610030943 fast
mainline 3.16.41-031641.201702270232 fast
mainline 3.17.8-031708.201501081837 fast
mainline 3.18.0-031800.201412071935 fast
mainline 3.18.12-031812.201504221338 fast
mainline 3.18.18-031818.201507101433 fast
mainline 3.18.21-031821.201509020527 fast
mainline 3.18.22-031822.201510031227 slow
mainline 3.18.23-031823.201510291931 slow
mainline 3.18.24-031824.201511031331 slow
mainline 3.18.47-031847.201701181631 slow
mainline 4.10.1-041001.201702260735 slow
---
AlsaDevices:
total 0
crw-rw---- 1 root audio 116, 1 Feb 28 10:29 seq
crw-rw---- 1 root audio 116, 33 Feb 28 10:29 timer
AplayDevices: Error: [Errno 2] No such file or directory
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq',
'/dev/snd/timer'] failed with exit code 1:
DistroRelease: Ubuntu 16.04
IwConfig: Error: [Errno 2] No such file or directory
MachineType: HP ProLiant DL380e Gen8
Package: linux (not installed)
PciMultimedia:
ProcFB:
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-64-generic
root=/dev/mapper/rootvg-rootlv ro console=ttyS0,115200n8 noquiet nosplash
nomodeset
ProcVersionSignature: Ubuntu 4.4.0-64.85-generic 4.4.44
RelatedPackageVersions:
linux-restricted-modules-4.4.0-64-generic N/A
linux-backports-modules-4.4.0-64-generic N/A
linux-firmware 1.157.8
RfKill: Error: [Errno 2] No such file or directory
Tags: xenial xenial
Uname: Linux 4.4.0-64-generic x86_64
UnreportableReason: The report belongs to a package that is not installed.
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:
_MarkForUpload: False
dmi.bios.date: 08/02/2014
dmi.bios.vendor: HP
dmi.bios.version: P73
dmi.chassis.type: 23
dmi.chassis.vendor: HP
dmi.modalias:
dmi:bvnHP:bvrP73:bd08/02/2014:svnHP:pnProLiantDL380eGen8:pvr:cvnHP:ct23:cvr:
dmi.product.name: ProLiant DL380e Gen8
dmi.sys.vendor: HP
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1668557/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
