May 2018 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Not able to set smp_affinity for an IRQ on i.MX7
by Pintu Kumar May 11, 2018

May 11, 2018

Hi, I need one help. I am using i.MX7 Sabre board with kernel version 4.1.15 Let's say I am interested in GPIO number: 21 I wanted to set CPU affinity for particular GPIO->IRQ number, so I tried the below steps: root@10:~# echo 21 > /sys/class/gpio/export root@10:~# echo "rising" > /sys/class/gpio/gpio21/edge root@10:~# cat /proc/interrupts | grep 21 47: 0 0 gpio-mxc 21 Edge gpiolib root@10:~# cat /sys/class/gpio/gpio21/direction in root@10:~# cat /proc/irq/47/smp_affinity 3 root@10:~# echo 2 > /proc/irq/47/smp_affinity -bash: echo: write error: Input/output error But I get input/output error. When I debug further, found that irq_can_set_affinity is returning 0: [ 0.000000] genirq: irq_can_set_affinity (0): balance: 1, irq_data.chip: a81b7e48, irq_set_affinity: (null) [ 0.000000] write_irq_affinity: FAIL I also tried first setting /proc/irq/default_smp_affinity to 2 (from 3). This change is working, but the smp_affinity setting for the new IRQ is not working. When I try to set smp_affinity for mmc0, then it works. # cat /proc/interrupts | grep mmc 295: 55 0 GPCV2 22 Edge mmc0 296: 0 0 GPCV2 23 Edge mmc1 297: 52 0 GPCV2 24 Edge mmc2 root@10:~# echo 2 > /proc/irq/295/smp_affinity root@10:~# So, I wanted to know what are the conditions for which setting smp_affinity for an IRQ will work ? Is there any way by which I can set CPU affinity to a GPIO -> IRQ ? Whether, irq_set_affinity_hint() will work in this case ? Thanks, Pintu

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Re: Kernelnewbies Digest, Vol 89, Issue 14
by Tran Ly Vu May 11, 2018

May 11, 2018

Hi, Is eudyptula challenge still alive? Thanks On 20 April 2018 at 00:00, <kernelnewbies-request(a)kernelnewbies.org> wrote: > Send Kernelnewbies mailing list submissions to > kernelnewbies(a)kernelnewbies.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > or, via email, send a message with subject or body 'help' to > kernelnewbies-request(a)kernelnewbies.org > > You can reach the person managing the list at > kernelnewbies-owner(a)kernelnewbies.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Kernelnewbies digest..." > > > Today's Topics: > > 1. How can I disable compile optimization in kernel for friendly > debugging, Thanks (sizel) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 19 Apr 2018 16:58:40 +0800 (CST) > From: sizel <sizel(a)163.com> > To: kernelnewbies <kernelnewbies(a)kernelnewbies.org> > Subject: How can I disable compile optimization in kernel for friendly > debugging, Thanks > Message-ID: <623d8297.8a0f.162dd208d7b.Coremail.sizel(a)163.com> > Content-Type: text/plain; charset="gbk" > > An HTML attachment was scrubbed... > URL: <http://lists.kernelnewbies.org/pipermail/kernelnewbies/ > attachments/20180419/53df7387/attachment-0001.html> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies(a)kernelnewbies.org > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > ------------------------------ > > End of Kernelnewbies Digest, Vol 89, Issue 14 > ********************************************* >

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Should I build the perf again when I change the kernel options?
by Gioh Kim May 11, 2018

May 11, 2018

Hi, Should I build the perf again when I change the kernel options? I have 4.14.34 kernel on my desktop and I built perf for my self. I'd like to change some options. Should I rebuild perf perf again? And another case. If there are two machines that have the same kernel version and different kernel options. Should I build the perf for each machines? Or can I build the perf on one machine and use it on another machine? Thank you in advance! -- Best regards, Gioh Kim

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kernel image path
by Sumit Kumar May 8, 2018

May 8, 2018

Hi, When I do sb make in a Kernel sand box where is the resultant image stored ? -- Thanks and Regards, Sumit

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Is this maintainers list up to date ?
by Sumit Kumar May 8, 2018

May 8, 2018

Hi, Can someone please confirm if this maintainer's list if up to date : https://github.com/torvalds/linux/blob/master/MAINTAINERS -- Thanks and Regards, Sumit

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Re: where to send patch
by Alex Arvelaez May 8, 2018

May 8, 2018

On May 7, 2018 5:23 PM, Sumit Kumar <sumit686215(a)gmail.com> wrote: > > Hi, > > When I use get_maintainer.pl script it give a list of names / addresses. > >1. Should I send to only one of them Send it to all of them, otherwise it's more likely it'll be lost in the noise. > 2. Should I put the first address in "To" field and the rest all in "CC" ? I believe you put the contributors in the To field and CC the relevant mailing list(s). There's a contribution guide you can read that explains this and more. (I'm paraphrasing so don't quote me) Regards, Alex

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(no subject)
by Vishnu Gopinath May 8, 2018

May 8, 2018

new in the field of linux kernal... how to start..from where to start

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where to send patch
by Sumit Kumar May 8, 2018

May 8, 2018

Hi, When I use get_maintainer.pl script it give a list of names / addresses. 1. Should I send to only one of them ? 2. Should I put the first address in "To" field and the rest all in "CC" ? -- Thanks and Regards, Sumit

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Compiler lacks asm go-to support
by Bhanusree Pola May 7, 2018

May 7, 2018

Hi all, I have cloned kernel from git clone -b staging-testing git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging while configuring the following error is shown arch/x86/Makefile:184: *** Compiler lacks asm-goto support.. Stop. I have tried all possible debugging with the help of internet,but could not solve the problem. Please help me in this regard Thanks & regards, Bhanusree Pola

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Re: how to identify kernel build in grub menu
by Alex Arvelaez May 7, 2018

May 7, 2018

On Apr 29, 2018 9:51 AM, Sumit Kumar <sumit686215(a)gmail.com> wrote: > > Hi, > > I built a kernel for the first time following this guide : > https://kernelnewbies.org/OutreachyfirstpatchSetup > > I rebooted my ubuntu machine and went to the grub menu and then chose > advanced option menu. I could see 5-6 different choices listed as Ubuntu > with different versions: > > 1. Are they all referring to some kernel build ? Yeah, check the kernel versions and you'll see that all entries are different. > 2. If so, how do I identify my build from the rest of the builds ? Is > there a way to name my build so that I can easily identify it ? There is an option to append a string to the version of the kernel. Use it to tag your kernels, you can find it by doing `make nconfig` I think it's under the "General" category(I'm paraphrasing) check the docs for the actual wording. Also after building and installing your new kernel you'll need to update your grub menu so it can detect the new kernel. Regards, Alex

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