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Date: Thu, 2 Jul 2026 15:58:28 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: <wang.yaxin@zte.com.cn>
Cc: <fan.yu9@zte.com.cn>, <yang.yang29@zte.com.cn>, <corbet@lwn.net>,
 <linux-kernel@vger.kernel.org>, <linux-doc@vger.kernel.org>,
 <xu.xin16@zte.com.cn>
Subject: Re: [PATCH 1/3] delaytop: add delay max for delaytop
Message-Id: <20260702155828.3b641339840e94917c165bd6@linux-foundation.org>
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On Thu, 2 Jul 2026 20:58:15 +0800 (CST) <wang.yaxin@zte.com.cn> wrote:

> From: Wang Yaxin <wang.yaxin@zte.com.cn>
> 
> Previously delaytop only showed average delays. Add delay_max fields to
> track the maximum delay value for each delay type (cpu, blkio, irq, swapin,
> freepages, thrashing, compact, wpcopy) per task.
> 
> This provides a global view of all tasks' delay spikes, which is essential
> for identifying processes that experienced brief but significant latency
> events that would be hidden by average-only metrics.
> 
> The -t/--type option displays only the specified delay type with avg/max
> values side by side, allowing focused analysis:
>   delaytop -t cpu    # Show only CPU delay with avg/max
>   delaytop -t wpcopy    # Show Copy-on-Write delay with avg/max
> 
> ...
> 
>  	total1 = *(unsigned long long *)((char *)t1 + cfg.sort_field->total_offset);

The code does this pointer operation in many places.  Is there a better
way?  Should all those `unsigned long long' fields in `struct
task_info' be in an array, something like that?