[PATCH] Add checking num-threads of makedumpfile

["Zhou, Wenjian/周文剑"]

Hello Minfei,

Thanks for your quick reply.

On 08/25/2015 01:42 PM, Minfei Huang wrote:
> On 08/25/15 at 12:51pm, Zhou Wenjian wrote:
>> A new feature that doing compressing and writing by multi-threads
>> has been added in makedumpfile. The thread num is specified by
>> "--num-threads NUM". According to its implementation, there will
>> be performance degradation if the threads are more than cpus.
>> So we should check it.
>>
>> Signed-off-by: Zhou wenjian <zhouwj-fnst at cn.fujitsu.com>
>> ---
>>   kdumpctl |   16 ++++++++++++++++
>>   1 files changed, 16 insertions(+), 0 deletions(-)
>>
>> diff --git a/kdumpctl b/kdumpctl
>> index b504734..a4b4681 100755
>> --- a/kdumpctl
>> +++ b/kdumpctl
>> @@ -259,6 +259,22 @@ check_config()
>>   		esac
>>   	done < $KDUMP_CONFIG_FILE
>>
>> +	grep -v "^#" $KDUMP_CONFIG_FILE | grep -q "num-threads"
>
> This filter cannot handle the all of the corner cases, like the
> following.
>
>   # grep -v "^#" /etc/kdump.conf  | grep "num-threads"
>   ext4 /dev/mapper/num-threads
>
> So it is better to use the exact regular expression to filter out the
> string. Maybe you can use $core_collector to filter out the string
> --num_threads.
>

I see.

>> +	if [ $? -eq 0 ];then
>> +		local nr_cpus=1
>> +		local num_threads=0
>> +		local core_collector=`grep -v "^#" $KDUMP_CONFIG_FILE | grep "^core_collector"`
>> +
>> +		num_threads=`echo ${core_collector#*--num-threads} | awk '{print $1}'`
>> +		nr_cpus=`echo ${KDUMP_COMMANDLINE_APPEND#*nr_cpus=} | awk '{print $1}'`
>> +
>> +		test $num_threads -ge $nr_cpus &> /dev/null
>> +		if [ $? -eq 0 ];then
>
> To keep the style, it is better to use "if [ $a -ge $b ]".
>

Using "test" is to handle the situation that the $num_threads or $nr_cpus is not an integer.

BTW, should we add some descriptions to this feature of makedumpfile in some where?

-- 
Thanks
Zhou