[PATCH v3] Improve the performance of --num-threads -d 31

["Zhou, Wenjian/周文剑"]

On 03/04/2016 05:07 PM, "Zhou, Wenjian/周文剑" wrote:
> Hello Minfei and Minoru,
>
> This is a reply to the previous letters.
> Sorry for so late.
> And it is also an introduction of the patch v3.
>
> About performance:
> I modified the patch after reading Minoru's code.
> Thanks Minoru, it has better performance now.
>
> About bugs:
> There are two bugs in the patch v2.
> First is reported by Minfei.
> Minoru's explanation and solution are right.
> But I used another solution.
> +            if (pfn >= kdump_thread_args->end_pfn) {
> +                page_data_buf[index].used = FALSE;
> +                page_flag_buf->ready = FLAG_READY;
> +                break;
> +            }
> The bug is caused by the above code.
> Just remove "page_flag_buf->ready = FLAG_READY;" is OK.
>
> Second bug is what I met.
> If run makedumpfile a lot of times, a few pages' data will not be correct.
> I fix it by using "volatile" and info->page_data_mutex.
> So I delete the original mutex in page_data_buf. It can also use less memory.
> I have run it 500 times and haven't got any wrong page data.
>

Sorry, the second bug still exists.


-- 
Thanks
Zhou