23 Jun
2011
23 Jun
'11
8:17 a.m.
On Wed, 2011-06-22 at 21:25 +0000,
linux-audio-user-request(a)lists.linuxaudio.org wrote:
Message: 16
Date: Wed, 22 Jun 2011 17:54:40 +0100
From: Rui Nuno Capela
Subject: Re: [LAU] Kernel 2.6.39
To: linux-audio-user(a)lists.linuxaudio.org
Message-ID: <4E021E50.80209(a)rncbc.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
if you're about to (aka. -rt) kernel the best
you can, with increased reliability on SCHED_FF scheduling (aka.
realtime scheduling, which is "bread & butter" for the whole jack
ecosystem) and provided you turn on the forced irq threads kernel
boot
option (threadirqs) then PREEMPT is certainly the one to configure
your
custom kernel.
beware, VOLUNTARY_PREEMPT (intended for general purpose desktops?)
and
PREEMPT_NONE (certainly only for servers?) will just give you lousy,
xrun-prone system, with no resemblance whatsoever with a good old but
true -rt kernel ;)
Hi Rui :)
I used the config from the self-build kernel 2.6.33.9-rt31 and run
oldconfig only to configure 2.6.39. I didn't make music until now using
this kernel. Yes, I wish to "emulate" the PREEMPT_RT, since common
PREEMPT only kernels never did, what I needed.
What do I need to set?
$ cat config-2.6.39.1 | grep PREEMPT
CONFIG_TREE_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
IIUC this is correct?!
Cheers!
Ralf
PS: SCHED_FF?
$ cat config-2.6.39.1 | grep SCHED
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y
# CONFIG_CGROUP_SCHED is not set
# CONFIG_SCHED_AUTOGROUP is not set
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_DEADLINE=y
CONFIG_IOSCHED_CFQ=y
CONFIG_CFQ_GROUP_IOSCHED=y
CONFIG_DEFAULT_IOSCHED="cfq"
CONFIG_SCHED_OMIT_FRAME_POINTER=y
CONFIG_SCHED_SMT=y
CONFIG_SCHED_MC=y
CONFIG_SCHED_HRTICK=y
CONFIG_NET_SCHED=y
CONFIG_USB_EHCI_TT_NEWSCHED=y
$ cat config-2.6.39.1 | grep FF
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
CONFIG_CDROM_PKTCDVD_BUFFERS=8
CONFIG_BLK_DEV_IDEDMA_SFF=y
# CONFIG_BLK_DEV_OFFBOARD is not set
# Controllers with non-SFF native interface
CONFIG_ATA_SFF=y
# SFF controllers with custom DMA interface
# SATA SFF controllers with BMDMA
# PATA SFF controllers with BMDMA
# PIO-only SFF controllers
CONFIG_INPUT_FF_MEMLESS=m
CONFIG_JOYSTICK_XPAD_FF=y
CONFIG_IPMI_POWEROFF=m
# CONFIG_SPI_TOPCLIFF_PCH is not set
CONFIG_FRAMEBUFFER_CONSOLE=y
CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y
CONFIG_DRAGONRISE_FF=y
# CONFIG_HID_EMS_FF is not set
CONFIG_LOGITECH_FF=y
CONFIG_LOGIRUMBLEPAD2_FF=y
# CONFIG_LOGIG940_FF is not set
# CONFIG_LOGIWII_FF is not set
CONFIG_PANTHERLORD_FF=y
CONFIG_GREENASIA_FF=y
CONFIG_SMARTJOYPLUS_FF=y
CONFIG_THRUSTMASTER_FF=y
CONFIG_ZEROPLUS_FF=y
# CONFIG_EDD_OFF is not set
CONFIG_AFFS_FS=m
CONFIG_JFFS2_FS=m
CONFIG_JFFS2_FS_DEBUG=0
CONFIG_JFFS2_FS_WRITEBUFFER=y
# CONFIG_JFFS2_FS_WBUF_VERIFY is not set
CONFIG_JFFS2_SUMMARY=y
CONFIG_JFFS2_FS_XATTR=y
CONFIG_JFFS2_FS_POSIX_ACL=y
CONFIG_JFFS2_FS_SECURITY=y
CONFIG_JFFS2_COMPRESSION_OPTIONS=y
CONFIG_JFFS2_ZLIB=y
CONFIG_JFFS2_LZO=y
CONFIG_JFFS2_RTIME=y
# CONFIG_JFFS2_RUBIN is not set
# CONFIG_JFFS2_CMODE_NONE is not set
CONFIG_JFFS2_CMODE_PRIORITY=y
# CONFIG_JFFS2_CMODE_SIZE is not set
# CONFIG_JFFS2_CMODE_FAVOURLZO is not set
CONFIG_RING_BUFFER=y
CONFIG_RING_BUFFER_ALLOW_SWAP=y
23 Jun
23 Jun
9:41 a.m.
New subject: Kernel 2.6.39
On 06/23/2011 07:17 AM, Ralf Mardorf wrote:
I used the config from the self-build kernel 2.6.33.9-rt31 and run
oldconfig only to configure 2.6.39. I didn't make music until now using
this kernel. Yes, I wish to "emulate" the PREEMPT_RT, since common
PREEMPT only kernels never did, what I needed.
What do I need to set?
$ cat config-2.6.39.1 | grep PREEMPT
CONFIG_TREE_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
IIUC this is correct?!
yes.
and don't forget to add "threadirqs" to your kernel bootloader
line--only then you'll get "rtirq" to do its magic as it used to do on a
genuine -rt kernel.
PS: SCHED_FF?
SCHED_FF is a process/thread attribute, not a kernel configuration
option--jack does that for you when told to run with realtime scheduling.
byee
--
rncbc aka Rui Nuno Capela
rncbc(a)rncbc.org
9:59 a.m.
New subject: Kernel 2.6.39
--- On Thu, 6/23/11, Rui Nuno Capela <rncbc(a)rncbc.org> wrote:
From: Rui Nuno Capela <rncbc(a)rncbc.org>
Subject: Re: [LAU] Kernel 2.6.39
To: linux-audio-user(a)lists.linuxaudio.org
Date: Thursday, June 23, 2011, 3:42 AM
On 06/23/2011 07:17 AM, Ralf Mardorf
wrote:
And remember to use /etc/default/grub to have this threadirqs boot option permanent:
/etc/default/grub : GRUB_CMDLINE_LINUX="threadirqs"
if you are too lazy to compile / recompile /etc, just use the liquorix debian kernel
(http://liquorix.net/)
I use that one (kernel compiled with CONFIG_PREEMPT=y, threadirqs at boot). It does
wonders! I tried the cyclictest mentioned by Rui and I got some quite outstanding numbers
on my system.
(However, the liquorix kernel is not PAE, which prevents the use of more than 4GB RAM for
32bit systems with more than 4GB of physical RAM)
J.
I used the config from the self-build kernel
2.6.33.9-rt31 and run
oldconfig only to configure 2.6.39. I didn't
make
music until now using
this kernel. Yes, I wish to "emulate"
the PREEMPT_RT,
since common
PREEMPT only kernels never did, what I needed.
What do I need to set?
$ cat config-2.6.39.1 | grep PREEMPT
CONFIG_TREE_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
IIUC this is correct?!
yes.
and don't forget to add "threadirqs" to your kernel
bootloader
line--only then you'll get "rtirq" to do its magic as it
used to do on a
genuine -rt kernel.
12:02 p.m.
New subject: Kernel 2.6.39
Hi,
Rui Nuno Capela wrote:
On 06/23/2011 07:17 AM, Ralf Mardorf wrote:
I'm just setting up a new computer, and I also installed the same 2.6.39
kernel...
I guess that passing "threadirqs" as a kernel argument is equivalent to
have CONFIG_IRQ_FORCED_THREADING=y as a kernel option. Am I right?
Best regards,
Natanael.
I used the config from the self-build kernel 2.6.33.9-rt31 and run
oldconfig only to configure 2.6.39. I didn't make music until now using
this kernel. Yes, I wish to "emulate" the PREEMPT_RT, since common
PREEMPT only kernels never did, what I needed.
What do I need to set?
$ cat config-2.6.39.1 | grep PREEMPT
CONFIG_TREE_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
IIUC this is correct?!
yes.
and don't forget to add "threadirqs" to your kernel bootloader
line--only then you'll get "rtirq" to do its magic as it used to do on
a genuine -rt kernel.
12:43 p.m.
New subject: Kernel 2.6.39
--- On Thu, 6/23/11, Natanael Olaiz <nolaiz(a)gmail.com> wrote:
From: Natanael Olaiz <nolaiz(a)gmail.com>
Subject: Re: [LAU] Kernel 2.6.39
To: linux-audio-user(a)lists.linuxaudio.org
Date: Thursday, June 23, 2011, 6:05 AM
Hi,
Rui Nuno Capela wrote:
bootloader
no it's not. One is a boot argument, the other is a kernel compilation config option
which matters if you compile the kernel. The boot argument will of course only work at
runtime if the config option had been turned on before compiling the kernel.
J.
On 06/23/2011 07:17 AM, Ralf Mardorf wrote:
>
> I used the config from the self-build kernel
2.6.33.9-rt31 and run
> oldconfig only to configure 2.6.39. I
didn't make
music until now using
> this kernel. Yes, I wish to
"emulate" the
PREEMPT_RT, since common
PREEMPT
only kernels never did, what I needed.
What do I need to set?
$ cat config-2.6.39.1 | grep PREEMPT
CONFIG_TREE_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
IIUC this is correct?!
yes.
and don't forget to add "threadirqs" to your kernel line--only then you'll get "rtirq"
to do its magic as
it used to do on
a genuine -rt kernel.
I'm just setting up a new computer, and I also installed
the same 2.6.39
kernel...
I guess that passing "threadirqs" as a kernel argument is
equivalent to
have CONFIG_IRQ_FORCED_THREADING=y as a kernel option. Am I
right?
4:17 p.m.
New subject: Kernel 2.6.39
On Thursday 21 Sivan 5771 10:42:15 Rui Nuno Capela wrote:
On 06/23/2011 07:17 AM, Ralf Mardorf wrote:
This is what I get from a plain Debian kernel:
david@dovidhalevi:~$ grep PREEMPT /boot/config-2.6.39-1-686-pae
# CONFIG_PREEMPT_RCU is not set
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
CONFIG_PREEMPT_VOLUNTARY=y
# CONFIG_PREEMPT is not set
david@dovidhalevi:~$ grep IRQ_FORCE /boot/config-2.6.39-1-686-pae
CONFIG_IRQ_FORCED_THREADING=y
Probably not enough.
I used the config from the self-build kernel
2.6.33.9-rt31 and run
oldconfig only to configure 2.6.39. I didn't make music until now using
this kernel. Yes, I wish to "emulate" the PREEMPT_RT, since common
PREEMPT only kernels never did, what I needed.
What do I need to set?
$ cat config-2.6.39.1 | grep PREEMPT
CONFIG_TREE_PREEMPT_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
IIUC this is correct?!
yes.
and don't forget to add "threadirqs" to your kernel bootloader
line--only then you'll get "rtirq" to do its magic as it used to do on a
genuine -rt kernel.
PS: SCHED_FF?
SCHED_FF is a process/thread attribute, not a kernel configuration
option--jack does that for you when told to run with realtime scheduling.
4904
days inactive
4904
days old
linux-audio-user@lists.linuxaudio.org
5 comments
5 participants
participants (5)
-
David Baron -
James Warden -
Natanael Olaiz -
Ralf Mardorf -
Rui Nuno Capela