Re: [LTP] [PATCH v6 1/2] mem/lib: add vm tunable file read/write/check func

Wanlong Gao
2011-12-28T08:14:06Z

On 12/28/2011 04:10 PM, Caspar Zhang wrote:

> On 12/28/2011 03:48 PM, Wanlong Gao wrote:
>> On 12/28/2011 02:47 PM, Caspar Zhang wrote:
>>
>>> On 11/15/2011 09:14 PM, Zhouping Liu wrote:
>>>> hi, Cyril & Garrett
>>>> v5 -> v6: updated the sscanf() function in read_meminfo() in order to avoid buffer overflow.
>>>>
>>>> please feel free to comment the patch.
>>>> BTW: you would miss the patch.
>>>>
>>>> There are several vm tunable files under /proc/sys/vm, I will compose
>>>> some cases for testing the basic functions of them. This patch is adding
>>>> the read/write/check functions to mem lib so that I can include them in
>>>> my testcases.
>>>>
>>>> set_sys_tune(): set a long long integer value to a vm tunable file.
>>>> get_sys_tune(): get a long long integer value from a vm tunable file.
>>>> check_sys_tune(): check to confirm the value in tunable file meets our
>>>> expectation.
>>>> read_meminfo(): read the special value from /proc/meminfo.
>>>>
>>>> Since most of the values in vm tunable files contain only single
>>>> integer, the functions I added only read/write long long values for now.
>>>> For those files not storing single interger (e.g. lowmem_reserve_ratio),
>>>> these functions will not be used in the case.
>>>>
>>>> Signed-off-by: Zhouping Liu <zliu@redhat.com>
>>>> ---
>>>> runtest/mm | 7 +++
>>>> testcases/kernel/mem/include/mem.h | 7 +++
>>>> testcases/kernel/mem/lib/mem.c | 84 +++++++++++++++++++++++++++++++++++-
>>>> 3 files changed, 97 insertions(+), 1 deletions(-)
>>>
>>> After talking to Zhouping Liu, I committed this patch with some
>>> modifications.
>>
>>
>> I saw that the patch you just committed defined an unused "PATH_SYSVM",
>> but as your comment of this patch, the set/get functions is just for sysfiles
>> under PATH_SYSVM, if so, you should do things like below first?
>>
>> snprintf(buf, BUFSIZ, "%s%s", PATH_KSM, path);
>
> Hi, the original design was to pass full path to set/get_sys_tune()
> functions, PATH_SYSVM will be used in other files. I agree with your
> idea, it looks like sys_file is better to be filename only. I'll merge

> your request.
>

Yeah, after this, I can then use set_sys_tune() in my patches.

Thanks
-Wanlong Gao

> Thanks,
> Caspar