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Message-ID: <56E6CD43.3010400@linaro.org>
Date: Mon, 14 Mar 2016 14:40:03 +0000
From: Kieran Bingham <kieran.bingham@...aro.org>
To: Jan Kiszka <jan.kiszka@...mens.com>, linux-kernel@...r.kernel.org
Cc: lee.jones@...aro.org, peter.griffin@...aro.org,
maxime.coquelin@...com
Subject: Re: [PATCHv3 00/13] scripts/gdb: Linux awareness debug commands
On 13/03/16 16:35, Jan Kiszka wrote:
> On 2016-03-03 12:40, Kieran Bingham wrote:
>> Hi Jan,
>>
>> V3 of the patchset respun. Now finally adding the lx-interrupts command
>> after I resolved my issues with the Radix Tree parsing.
>>
>> This command only provides the interrupts that are available generically,
>> and it seems that the /proc/interrupts function calls into arch specific
>> layers to add extra information about arch specific interrupts.
>>
>> I'm not sure what to do about this yet - The values returned appear to be
>> accurate - but it's just a subset of the information returned by proc.
>>
>
> I didn't test this (due to the breakage in patch 10): Can you give
> examples of what is missing, e.g. on ARM or x86?
On ARM this is :
(gdb) lx-interrupts
CPU0 CPU1
18: 587828 150187
36: 66574 0
41: 8 0
42: 106 0
43: 100 0
(gdb) c
vs
root@...ACookieMonster:~# cat /proc/interrupts
CPU0 CPU1
18: 588057 150274 GIC-0 27 Edge arch_timer
20: 0 0 GIC-0 34 Level timer
36: 66599 0 GIC-0 47 Level eth0
39: 0 0 GIC-0 41 Level mmci-pl18x (cmd)
40: 0 0 GIC-0 42 Level mmci-pl18x (pio)
41: 8 0 GIC-0 44 Level kmi-pl050
42: 106 0 GIC-0 45 Level kmi-pl050
43: 112 0 GIC-0 37 Level uart-pl011
49: 0 0 GIC-0 36 Level rtc-pl031
IPI0: 0 1 CPU wakeup interrupts
IPI1: 0 0 Timer broadcast interrupts
IPI2: 15867 281362 Rescheduling interrupts
IPI3: 0 6 Function call interrupts
IPI4: 0 0 CPU stop interrupts
IPI5: 0 0 IRQ work interrupts
IPI6: 0 0 completion interrupts
Err: 0
So quite a substantial subset :(
>
>> lx_thread_info_by_pid has been useful to me while looking at thread
>> awareness, so I've included it into this patch set now. It makes finding
>> internal thread information much more convenient.
>>
>> dentry_name has been moved to the utils module, as I am already using it
>> in another command, so it's just not appropriate to be in proc.py
>>
>> The cpu_list mask iterators make calling for cpu in each_online_cpu() read
>> nicely, and I've left the print_cpus() function in for now as a hidden
>> helper. It can be used by calling:
>> python linux.cpus.print_cpus()
>> to check these generators, which I thought was quite nice - but I didn't
>> know if it warranted a full command class for this.
>>
>> For convenience, this patch set submission can be found at
>> http://git.linaro.org/people/kieran.bingham/linux.git gdb-scripts-2016-03-03-lkml-submission
>>
>> Patchset Changelog:
>> v3:
>> - Radix Tree parser introduced
>> - cpu_list mask iterators added
>> - lx-interrupts command implemented
>> - dentry_name function moved to utils
>> - lx-meminfo command PEP8 warnings fixed
>> - lx_thread_info_by_pid introduced
>>
>> v2:
>> - Reworked iterators with improved versions from Jeff Mahoney
>> - Fixed !CONFIG_MODULES and !CONFIG_MMU support
>> - Improvements on lx-meminfo
>> - constants.py generated by Kbuild
>> - IS_BUILTIN facility used to provide LX_CONFIG values
>>
>> v1:
>> - Introduced lx-iomem, lx-ioports, lx-mounts, lx-meminfo
>>
>> Kieran Bingham (13):
>> scripts/gdb: Provide linux constants
>> scripts/gdb: Provide kernel list item generators
>> scripts/gdb: Convert modules usage to lists functions
>> scripts/gdb: Provide exception catching parser
>> scripts/gdb: Support !CONFIG_MODULES gracefully
>> scripts/gdb: Provide a dentry_name VFS path helper
>> scripts/gdb: Add io resource readers
>> scripts/gdb: Add mount point list command
>> scripts/gdb: Add meminfo command
>> scripts/gdb: Add cpu iterators
>> scripts/gdb: Add a Radix Tree Parser
>> scripts/gdb: Add interrupts command
>> scripts/gdb: Add lx_thread_info_by_pid helper
>>
>> Kbuild | 10 +
>> scripts/gdb/linux/Makefile | 12 +-
>> scripts/gdb/linux/constants.py.in | 93 ++++++++
>> scripts/gdb/linux/cpus.py | 21 ++
>> scripts/gdb/linux/lists.py | 20 ++
>> scripts/gdb/linux/modules.py | 22 +-
>> scripts/gdb/linux/proc.py | 449 ++++++++++++++++++++++++++++++++++++++
>> scripts/gdb/linux/radixtree.py | 74 +++++++
>> scripts/gdb/linux/tasks.py | 19 ++
>> scripts/gdb/linux/utils.py | 15 ++
>> scripts/gdb/vmlinux-gdb.py | 2 +
>> 11 files changed, 724 insertions(+), 13 deletions(-)
>> create mode 100644 scripts/gdb/linux/constants.py.in
>> create mode 100644 scripts/gdb/linux/radixtree.py
>>
>
> Besides the required rebase and, thus, the missing adjustment of the cpu
> masks, I only have minor remarks. Maybe I will have more once I can play
> with lx-interrupts ;).
Ok - well it's fixed up locally, it's just a matter of prefixing the
strings with two underscores. I should be able to get the updated
patches out soon I hope.
> However, I have a growing concern - I think we already discussed this
> offline: Without automated tests, all these helpers may quickly fall
> apart as the kernel changes. This should not block these patches, but
> maybe you can think about some testing approaches before we have dozens
> of helpers which can only be validated manually.
Yes, indeed - and the breakage already seen between v4.4 and v4.5 only
solidifies the need!
I was able to chat to a few of the Linaro LAVA guys on this topic while
I was at Connect, and they already have virtual kernels being boot
tested. This should provide a good infrastructure to run some automated
tests on.
So we have the infrastructure - we just need to get the tests written,
and included.
--
Kieran
> Thanks,
> Jan
>
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