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CarstenIQ n00b
Joined: 04 Jan 2007 Posts: 44 Location: Germany
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Posted: Mon Sep 03, 2012 3:54 pm Post subject: |
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I ended up in using the pf-sources (3.5.2) with the BFQ patch set and zram. My 4 core Phenom II works smooth in x86_64 environment.
I works so good that the Flash player doesn't even crash anymore in Opera. For me the gentoo-sources (3.4.9 ) was just to sluggish and had too many lock-ups. It might be a considered a stable kernel but for me it is not usable kernel in x86_64 environment. _________________ Gentoo Linux Rocks...!!! |
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yoshi314 l33t
Joined: 30 Dec 2004 Posts: 850 Location: PL
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Posted: Wed Sep 05, 2012 11:16 am Post subject: |
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btw, running vanilla kernel i noticed that unrar command is incredibly slow. (similariy when unpacking the file with 7z)
unpacking a 3GB archive took well over an hour. is anyone else catching the same issue when not doing any performance improving workarounds?
edit: it stopped happening recently, for some reason. _________________ ~amd64
shrink your /usr/portage with squashfs+aufs
Last edited by yoshi314 on Mon Nov 26, 2012 8:51 am; edited 1 time in total |
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smlbstcbr n00b
Joined: 08 Apr 2006 Posts: 51
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Posted: Sat Nov 24, 2012 1:23 am Post subject: |
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Bump. Using kernel 3.5.7 and the deadline scheduler the problem is greatly reduced. Tough also modifying the PCI latency timer seems to have had a significant impact in the responsiveness of the whole system. |
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_______0 Guru
Joined: 15 Oct 2012 Posts: 521
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Posted: Tue Dec 18, 2012 12:54 pm Post subject: how to use? |
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smlbstcbr wrote: | ... PCI latency timer seems to have had a significant impact in the responsiveness of the whole system. |
how to do this?? What's better higher values on all pci slots or something?
Also why on earth does setpci use hex values instead of more user-friendly NUMBERS???!!
Quote: | where xx:yy.z are the first numbers listed by lspci, and n is a hex value between 0 and ff (setpci will round down ff, which is actually 255, to the required 248). |
dis crazy... Ideally it'd be nice to have a web interface for setpci controlled by pretty sliders for each pci slot and with css shadows.
And for maximum priority for sound card (to prevent xruns) which value would be? Something like this?
Code: |
setpci -v -s 06:05.0 latency_timer=ff |
thanks.
I forgot to add, how do intenger values between 0 and 248 translate into hex values? It be nice to have it as reference. This is confusing because according to a blog setpci hex values are ODD numbers instead of even oO
If anybody know this I need a table of the exact ODD setpci hex value with the corresponding BIOS even values, like this.
hex | hex odd intenger | bios even intenger
ff 255 248
here is the referenced site http://www.mythtv.org/wiki/PCI_Latency
And to expand on this topic. How can person determine which is the best combination of latency for all devices in order for a computer to run optimal?? Let's say I know now that I want to prevent the sound card to have xruns the set it to maximum priority, then for recording the hard drive would need an optimal value too. It's not accurate just to set something high because it 'feels' it'll run better. |
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smlbstcbr n00b
Joined: 08 Apr 2006 Posts: 51
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yoshi314 l33t
Joined: 30 Dec 2004 Posts: 850 Location: PL
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mack1 Guru
Joined: 18 Mar 2006 Posts: 315
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Posted: Wed Mar 20, 2013 5:36 pm Post subject: |
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I have installed git-sources-3.9-r3 and high latency is greatly reduced under heavy i/o operations ! |
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smlbstcbr n00b
Joined: 08 Apr 2006 Posts: 51
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Posted: Thu Mar 21, 2013 9:38 pm Post subject: |
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Really?! I had noticed a significant improvement by using the RCU option in 3.7.10 with the deadline scheduler. |
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depontius Advocate
Joined: 05 May 2004 Posts: 3509
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Posted: Thu Mar 21, 2013 11:20 pm Post subject: |
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smlbstcbr wrote: | Really?! I had noticed a significant improvement by using the RCU option in 3.7.10 with the deadline scheduler. |
I've at least heard of the deadline scheduler, though I use the default CFQ. I've also read of RCU, but I thought that was just plain baked-in as a feature to be used by other subsystems, especially handy for multiprocessor.
What is "the RCU option"? _________________ .sigs waste space and bandwidth |
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smlbstcbr n00b
Joined: 08 Apr 2006 Posts: 51
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Posted: Fri Mar 22, 2013 3:42 pm Post subject: |
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depontius wrote: | smlbstcbr wrote: | Really?! I had noticed a significant improvement by using the RCU option in 3.7.10 with the deadline scheduler. |
I've at least heard of the deadline scheduler, though I use the default CFQ. I've also read of RCU, but I thought that was just plain baked-in as a feature to be used by other subsystems, especially handy for multiprocessor.
What is "the RCU option"? |
https://www.kernel.org/doc/Documentation/RCU/rcu.txt |
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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smlbstcbr n00b
Joined: 08 Apr 2006 Posts: 51
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Posted: Sat Mar 23, 2013 9:41 pm Post subject: |
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Here it is
Code: |
# RCU Subsystem
#
CONFIG_TINY_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
# CONFIG_TREE_RCU_TRACE is not set
CONFIG_RCU_BOOST=y
CONFIG_RCU_BOOST_PRIO=1
CONFIG_RCU_BOOST_DELAY=500 |
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Mr.EVIL n00b
Joined: 22 Mar 2013 Posts: 10
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Posted: Sun Mar 24, 2013 7:04 pm Post subject: |
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it was fixable long time ago with "realtime" patches... |
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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Posted: Mon Mar 25, 2013 12:34 pm Post subject: |
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smlbstcbr wrote: | Here it is
Code: |
# RCU Subsystem
#
CONFIG_TINY_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
# CONFIG_TREE_RCU_TRACE is not set
CONFIG_RCU_BOOST=y
CONFIG_RCU_BOOST_PRIO=1
CONFIG_RCU_BOOST_DELAY=500 |
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thanks !
I believe though that most of us here already us a preemptible implementation of RCU
Mr.EVIL wrote: | it was fixable long time ago with "realtime" patches... |
unfortunately not an option with ZFS (?)
do you use virtualbox ? does that work for you with the rt-kernel ? _________________ https://github.com/kernelOfTruth/ZFS-for-SystemRescueCD/tree/ZFS-for-SysRescCD-4.9.0
https://github.com/kernelOfTruth/pulseaudio-equalizer-ladspa
Hardcore Gentoo Linux user since 2004 |
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depontius Advocate
Joined: 05 May 2004 Posts: 3509
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Posted: Mon Mar 25, 2013 12:53 pm Post subject: |
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smlbstcbr wrote: | Here it is
Code: |
# RCU Subsystem
#
CONFIG_TINY_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
# CONFIG_TREE_RCU_TRACE is not set
CONFIG_RCU_BOOST=y
CONFIG_RCU_BOOST_PRIO=1
CONFIG_RCU_BOOST_DELAY=500 |
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Just a side-note... The CONFIG_PREEMPT_RCU option doesn't even show unless you're building a preemptible kernel. I normally build with "voluntary preemption," but this weekend when building 3.8.4 I went the pre-emptible route, and ticked CONFIG_PREEMPT_RCU=y. I don't think I ticked CONFIG_TINY_PREEMPT_RCU - I really need to go back and read if I should have used it for a mere dual-core CPU.
EDIT - a few typos, a little clarification. _________________ .sigs waste space and bandwidth
Last edited by depontius on Mon Mar 25, 2013 3:36 pm; edited 1 time in total |
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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ryao Retired Dev
Joined: 27 Feb 2012 Posts: 132
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Posted: Mon Mar 25, 2013 5:43 pm Post subject: |
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kernelOfTruth wrote: | Mr.EVIL wrote: | it was fixable long time ago with "realtime" patches... |
unfortunately not an option with ZFS (?)
do you use virtualbox ? does that work for you with the rt-kernel ? |
Why is that? If there is an incompatibility, I would like a bug report. |
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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ryao Retired Dev
Joined: 27 Feb 2012 Posts: 132
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Posted: Mon Mar 25, 2013 8:18 pm Post subject: |
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I had missed this when looking through the bug tracker. Thanks for bringing it to my attention. I will see what I can do to fix the build failure. |
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ryao Retired Dev
Joined: 27 Feb 2012 Posts: 132
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Posted: Mon Mar 25, 2013 9:16 pm Post subject: |
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I tried building a 3.8.4 realtime kernel and was promptly greeted by a build failure for the kernel source tree itself:
Code: | */usr/src/linux/kernel/events/uprobes.c:1143: undefined reference to `percpu_down_read'
*kernel/built-in.o: In function `uprobe_end_dup_mmap':
*/usr/src/linux/kernel/events/uprobes.c:1148: undefined reference to `percpu_up_read'
*kernel/built-in.o: In function `init_uprobes':
*/usr/src/linux/kernel/events/uprobes.c:1617: undefined reference to `__percpu_init_rwsem' |
I cannot produce a fix for ZFS unless I have a fix for this and I do not have time to fix issues in other people's kernel code right now. :/ |
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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Posted: Mon Mar 25, 2013 9:39 pm Post subject: |
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ryao wrote: | I tried building a 3.8.4 realtime kernel and was promptly greeted by a build failure for the kernel source tree itself:
Code: | */usr/src/linux/kernel/events/uprobes.c:1143: undefined reference to `percpu_down_read'
*kernel/built-in.o: In function `uprobe_end_dup_mmap':
*/usr/src/linux/kernel/events/uprobes.c:1148: undefined reference to `percpu_up_read'
*kernel/built-in.o: In function `init_uprobes':
*/usr/src/linux/kernel/events/uprobes.c:1617: undefined reference to `__percpu_init_rwsem' |
I cannot produce a fix for ZFS unless I have a fix for this and I do not have time to fix issues in other people's kernel code right now. :/ |
I'll have a look at it & see whether I get it to build reliably within the next days
thanks again
on-topic:
using the latency-timer tweaks + BFS and I couldn't observe any sound stuttering so far
even while compiling GCC which ALWAYS had resulted in at least some minor stuttering or lag on the GUI & sound
I also followed advice and use schedtool on X & pulseaudio
Code: | schedtool -p 0 -n -20 -N `pgrep X`
schedtool -p 0 -n -20 -N `pgrep pulseaudio` |
_________________ https://github.com/kernelOfTruth/ZFS-for-SystemRescueCD/tree/ZFS-for-SysRescCD-4.9.0
https://github.com/kernelOfTruth/pulseaudio-equalizer-ladspa
Hardcore Gentoo Linux user since 2004 |
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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kernelOfTruth Watchman
Joined: 20 Dec 2005 Posts: 6111 Location: Vienna, Austria; Germany; hello world :)
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yoshi314 l33t
Joined: 30 Dec 2004 Posts: 850 Location: PL
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Posted: Mon Jun 10, 2013 9:02 am Post subject: |
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i'm going to try this.
So far the only major issue i have is when copying big files (1.5-2GB) to usb. probably due to memory pressure or something, everything slows down to a crawl until the file is copied over, especially during final 10% of the copy process (when using mc or bar application).
That's on 64bit system with core2 cpu and 3gb of ram. It hits pretty hard with ck-3.9 kernel, with no further manual tweaks. _________________ ~amd64
shrink your /usr/portage with squashfs+aufs |
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ulenrich Veteran
Joined: 10 Oct 2010 Posts: 1480
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Posted: Mon Jun 10, 2013 4:32 pm Post subject: |
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yoshi314 wrote: | So far the only major issue i have is when copying big files (1.5-2GB) to usb. probably due to memory pressure or something, everything slows down |
Yes, for me using mc too. I suspect caching. Why the hell we need normal caching?
We need a special purpose cache for copying:
read-cache-write-forget
No fighting over obsolete data wants to keep staying in cache ...
Or is it just the old midnight source code missing to use an existing special Linux kernel function? |
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