[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <56E6F26A.2070907@linaro.org>
Date: Mon, 14 Mar 2016 17:18:34 +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 14/03/16 15:09, Jan Kiszka wrote:
> On 2016-03-14 15:40, Kieran Bingham wrote:
>> 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 :(
>
> Indeed. Given this delta, I'm reluctant to include that command at this
> point.
Ok, understandable...
I think the radix-tree lookup could be useful for people though.
This is used across filesystems, and other places.
Perhaps I should wrap this up into a gdb.Function rather than drop it?
>>>> 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.
>
> Sounds good!
>
>>
>> So we have the infrastructure - we just need to get the tests written,
>> and included.
>
> Yeah, "minor" detail.
Isn't it ever :D
>
> Jan
>
Powered by blists - more mailing lists