linux-kernel - Re: Re: [PATCH V5 4/5] cachefiles: narrow the scope of triggering EPOLLIN events in ondemand mode

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Message-ID: <1a9c4365-aae1-b4fe-d31d-dfd9b42afae6@bytedance.com>
Date:   Fri, 14 Apr 2023 22:13:30 +0800
From:   Jia Zhu <zhujia.zj@...edance.com>
To:     David Howells <dhowells@...hat.com>
Cc:     linux-cachefs@...hat.com, linux-erofs@...ts.ozlabs.org,
        linux-kernel@...r.kernel.org, jefflexu@...ux.alibaba.com,
        hsiangkao@...ux.alibaba.com, yinxin.x@...edance.com,
        zhujia.zj@...edance.com
Subject: Re: Re: [PATCH V5 4/5] cachefiles: narrow the scope of triggering
 EPOLLIN events in ondemand mode



在 2023/4/14 21:48, David Howells 写道:
> Jia Zhu <zhujia.zj@...edance.com> wrote:
> 
>>   	if (cachefiles_in_ondemand_mode(cache)) {
>> -		if (!xa_empty(&cache->reqs))
>> -			mask |= EPOLLIN;
>> +		if (!xa_empty(xa)) {
>> +			rcu_read_lock();
>> +			xa_for_each_marked(xa, index, req, CACHEFILES_REQ_NEW) {
>> +				if (!cachefiles_ondemand_is_reopening_read(req)) {
>> +					mask |= EPOLLIN;
>> +					break;
>> +				}
>> +			}
>> +			rcu_read_unlock();
> 
> You should probably use xas_for_each_marked() instead of xa_for_each_marked()
> as the former should perform better.
> 
> David

Hi David,

Thanks for your advice. I'll revise it in next version.

Jia
>