[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-users] Xen boot time optimization



Hi,
Thank you for your reply.I have enabled the CONFIG_DEBUG_LL in arch/arm/configs/odroidxu3_xen_defconfig and arch/arm/configs/odroidxu3_defconfig.And now i'm getting the print like
[2020-03-06 16:05:53.443] (XEN) Guest Loglevel: All
[2020-03-06 16:05:53.443] (XEN) Freed 264kB init memory.
[2020-03-06 16:05:55.111] (XEN) DOM0: Uncompressing Linux... done, booting the kernel.

and it is hanging there.But the print is not coming from XEN.it's coming from arch/arm/boot/compressed/misc.c of dom0 linux.It's quiet confusing and I couldn't figure out the problem.Please help


Regards,
Subhasree

On Fri, Mar 6, 2020 at 1:51 PM Bertrand Marquis <Bertrand.Marquis@xxxxxxx> wrote:

On 6 Mar 2020, at 05:50, Subhasree P V <subhasree.pv@xxxxxxxxxxxxxxxxxxx> wrote:

Thank you so much for your reply Bertrand.I have done it and was able to reduce about 520ms time..

Nice.

But still the delay before kernel load is the same.I think it is the time taken for the processing the interrupts.about 4s delay is there before kernel load.You can see it in the below log.

[2020-03-06 10:23:32.817] (XEN) Freed 264kB init memory.
[2020-03-06 10:23:36.719] [    0.000000] [c0] Booting Linux on physical CPU 0x0
[2020-03-06 10:23:36.719] [    0.000000] [c0] Initializing cgroup subsys cpu
[2020-03-06 10:23:36.724] [    0.000000] [c0] Initializing cgroup subsys cpuacct

I have tried by setting GICH_V2_LR_MAINTENANCE_IRQ only for non-hardware irqs and avoiding for hardware irqs.1s reduction in the delay has been there when i have done so.But dom0 kernel was not loading completely while doing so.It was hanging at some point.I thought the delay might be because of  too much inflight irqs.Could you please help me to solve it.


You are probably missing IRQs in Linux when you did that as the maintenance IRQ is needed by the vGIC.

Regarding the delay you see between “Freed” and first linux message it might be interesting to check if this time is actually spent in Xen or in Linux because the Freed is the last message printed by Xen here.

I cannot setup a system now to do some investigation on this but boot time with xen is something I will be definitely look at in the next months.

Regards
Bertrand


Thanks & Regards,
Subhasree






On Thu, Mar 5, 2020 at 10:47 PM Bertrand Marquis <Bertrand.Marquis@xxxxxxx> wrote:
Hi,

On 4 Mar 2020, at 10:40, Subhasree P V <subhasree.pv@xxxxxxxxxxxxxxxxxxx> wrote:

Hi,
I have been working with using XEN on ODROID-XU4 board.I would like to optimize the boot time of XEN to 3s. Currently it is taking about 5s to boot.I have disabled the prints.There is about 4s delay before kernel load.
Below is the log before disabling prints.
 
[2020-02-13 12:53:18.791] (XEN) Brought up 8 CPUs
[2020-02-13 12:53:18.791] (XEN) P2M: 40-bit IPA
[2020-02-13 12:53:18.791] (XEN) P2M: 3 levels with order-1 root, VTCR 0x80003558
[2020-02-13 12:53:18.797] (XEN) I/O virtualisation disabled
[2020-02-13 12:53:18.802] (XEN) *** LOADING DOMAIN 0 ***
[2020-02-13 12:53:18.802] (XEN) Loading kernel from boot module @ 0000000060000000
[2020-02-13 12:53:18.808] (XEN) Allocating 1:1 mappings totalling 1024MB for dom0:
[2020-02-13 12:53:19.578] (XEN) BANK[0] 0x00000070000000-0x000000b0000000 (1024MB)

This step takes 800ms

[2020-02-13 12:53:19.578] (XEN) Grant table range: 0x000000be800000-0x000000be861000
[2020-02-13 12:53:19.624] (XEN) Loading zImage from 0000000060000000 to 0000000077c00000-0000000077f08f60
[2020-02-13 12:53:19.649] (XEN) Allocating PPI 16 for event channel interrupt
[2020-02-13 12:53:19.649] (XEN) Loading dom0 DTB to 0x0000000078000000-0x000000007800c2f0
[2020-02-13 12:53:19.654] (XEN) Scrubbing Free RAM on 1 nodes using 8 CPUs

You probably want to disable scrubbing memory to speed up your boot (add bootscrub=no to your command line).

Regards
Bertrand


[2020-02-13 12:53:19.915] (XEN) ..done.
[2020-02-13 12:53:20.168] (XEN) Initial low memory virq threshold set at 0x4000 pages.
[2020-02-13 12:53:20.174] (XEN) Std. Loglevel: All
[2020-02-13 12:53:20.174] (XEN) Guest Loglevel: All
[2020-02-13 12:53:20.174] (XEN) Freed 264kB init memory.
[2020-02-13 12:53:24.274] [    0.000000] [c0] Booting Linux on physical CPU 0x0


I'm getting a delay after Freed 264kB init memory.I'm not able to figure out the reason for delay.Is there any way to reduce the delay?Please help me to solve this.


Thank you.

This message contains confidential information and is intended only for the individual(s) named. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this mail and attached file/s is strictly prohibited. Please notify the sender immediately and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secured or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message, which arise as a result of e-mail transmission.

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-users


This message contains confidential information and is intended only for the individual(s) named. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this mail and attached file/s is strictly prohibited. Please notify the sender immediately and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secured or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message, which arise as a result of e-mail transmission.



This message contains confidential information and is intended only for the individual(s) named. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this mail and attached file/s is strictly prohibited. Please notify the sender immediately and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secured or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message, which arise as a result of e-mail transmission.

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-users

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.