BFS Scheduler 0.446 Supports The Linux 3.13 Kernel

[phoronix]

Phoronix: BFS Scheduler 0.446 Supports The Linux 3.13 Kernel

For users of the BFS scheduler patches to the kernel, they have been updated this week for the Linux 3.13 kernel...

http://www.phoronix.com/vr.php?view=MTYyMzA

[zanny]

Just curious, to anyone who uses the ck or pf patchesets, do the bfs schedulers actually help fix that annoying "disk io (especially usb interrupt based) makes the system unresponsive" mess that happens on generic kernels? I'm finding myself doing a lot more large file transfers at 300+ MB/s and it cripples even my i7 rig for their duration.

[blackout23]

Just curious, to anyone who uses the ck or pf patchesets, do the bfs schedulers actually help fix that annoying "disk io (especially usb interrupt based) makes the system unresponsive" mess that happens on generic kernels? I'm finding myself doing a lot more large file transfers at 300+ MB/s and it cripples even my i7 rig for their duration.

BFS doesn't affect your disk. It's a CPU scheduler. You'd have to use BFQ for that and enable it with "elevator=bfq" in the kernel line first. Apparently it is designed to keep the system responsive at all times.

https://www.youtube.com/watch?v=J-e7LnJblm8

[kernelOfTruth]

Just curious, to anyone who uses the ck or pf patchesets, do the bfs schedulers actually help fix that annoying "disk io (especially usb interrupt based) makes the system unresponsive" mess that happens on generic kernels? I'm finding myself doing a lot more large file transfers at 300+ MB/s and it cripples even my i7 rig for their duration.

it mitigates things but, of course, doesn't fix a problem, that isn't caused by or inherent to the cpu scheduling part

"disk io (especially usb interrupt based) makes the system unresponsive"

so how exactly does this show itself ?

you have an SSD or raid harddrive enclosure attached to the USB 3.0 ports ? (referring to the usb interrupt part)


will post some tweaks once I'm on linux again, currently on Windows - gaming some (Origin doesn't allow to install Mass Effect 3 & other games also don't work)

[kernelOfTruth]

it mitigates things but, of course, doesn't fix a problem, that isn't caused by or inherent to the cpu scheduling part

"disk io (especially usb interrupt based) makes the system unresponsive"

so how exactly does this show itself ?

you have an SSD or raid harddrive enclosure attached to the USB 3.0 ports ? (referring to the usb interrupt part)


will post some tweaks once I'm on linux again, currently on Windows - gaming some (Origin doesn't allow to install Mass Effect 3 & other games also don't work)

echo "raise latency_timer for EHCI USB2.0"
# raise priority of others:
setpci -v -s 00:1a.0 latency_timer=80 # EHCI USB2.0
setpci -v -s 00:1d.0 latency_timer=80 # EHCI USB2.0

<-- of course modify according to your lspci output

echo 15 > /sys/devices/system/cpu/cpufreq/ondemand/up_threshold
echo 10 > /sys/devices/system/cpu/cpufreq/ondemand/sampling_down_factor

make sure that the:

dirty_expire_centisecs
dirty_writeback_centisecs
dirty_background_ratio
dirty_ratio

values are not too high


make sure the (and more) following patchsets are included in your kernel:

- [patch 0/2] mm: reduce reclaim stalls with heavy anon and dirty cache
- mm: add strictlimit knob; http://article.gmane.org/gmane.linux.kernel.mm/105809