Re: [PATCH v2 1/7] memcg: reduce memory size of mem_cgroup_events_index

From: Roman Gushchin <roman.gushchin@linux.dev>
To: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Michal Hocko <mhocko@kernel.org>,
	Muchun Song <muchun.song@linux.dev>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/7] memcg: reduce memory size of mem_cgroup_events_index
Date: Mon, 29 Apr 2024 08:36:12 -0700	[thread overview]
Message-ID: <Zi--bEqvwJHXqTLL@P9FQF9L96D> (raw)
In-Reply-To: <20240427003733.3898961-2-shakeel.butt@linux.dev>

On Fri, Apr 26, 2024 at 05:37:27PM -0700, Shakeel Butt wrote:
> mem_cgroup_events_index is a translation table to get the right index of
> the memcg relevant entry for the general vm_event_item. At the moment,
> it is defined as integer array. However on a typical system the max
> entry of vm_event_item (NR_VM_EVENT_ITEMS) is 113, so we don't need to
> use int as storage type of the array. For now just use int8_t as type
> and add a BUILD_BUG_ON() and will switch to short once NR_VM_EVENT_ITEMS
> touches 127.
> 
> Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>

Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>