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From:   David Howells <dhowells@redhat.com>
In-Reply-To: <20230329140155.53272-5-zhujia.zj@bytedance.com>
References: <20230329140155.53272-5-zhujia.zj@bytedance.com> <20230329140155.53272-1-zhujia.zj@bytedance.com>
To:     Jia Zhu <zhujia.zj@bytedance.com>
Cc:     dhowells@redhat.com, linux-cachefs@redhat.com,
        linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        jefflexu@linux.alibaba.com, hsiangkao@linux.alibaba.com,
        yinxin.x@bytedance.com
Subject: Re: [PATCH V5 4/5] cachefiles: narrow the scope of triggering EPOLLIN events in ondemand mode
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Content-ID: <1250224.1681480128.1@warthog.procyon.org.uk>
Date:   Fri, 14 Apr 2023 14:48:48 +0100
Message-ID: <1250225.1681480128@warthog.procyon.org.uk>
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Jia Zhu <zhujia.zj@bytedance.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