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Date: Thu, 30 Nov 2023 14:39:56 -0500
From: Johannes Weiner <hannes@cmpxchg.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>,
	Dan Schatzberg <schatzberg.dan@gmail.com>,
	Roman Gushchin <roman.gushchin@linux.dev>,
	Yosry Ahmed <yosryahmed@google.com>, Huan Yang <link@vivo.com>,
	linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
	linux-mm@kvack.org, Michal Hocko <mhocko@kernel.org>,
	Muchun Song <muchun.song@linux.dev>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Hildenbrand <david@redhat.com>,
	Huang Ying <ying.huang@intel.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Peter Xu <peterx@redhat.com>,
	"Vishal Moola (Oracle)" <vishal.moola@gmail.com>,
	Yue Zhao <findns94@gmail.com>, Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH 0/1] Add swappiness argument to memory.reclaim
Message-ID: <20231130193956.GA543908@cmpxchg.org>
References: <20231130153658.527556-1-schatzberg.dan@gmail.com>
 <20231130184424.7sbez2ukaylerhy6@google.com>
 <ZWjabcWQm/GUoGTf@casper.infradead.org>
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In-Reply-To: <ZWjabcWQm/GUoGTf@casper.infradead.org>

On Thu, Nov 30, 2023 at 06:54:37PM +0000, Matthew Wilcox wrote:
> On Thu, Nov 30, 2023 at 06:44:24PM +0000, Shakeel Butt wrote:
> > On Thu, Nov 30, 2023 at 07:36:53AM -0800, Dan Schatzberg wrote:
> > > * Swapout should be limited to manage SSD write endurance. In near-OOM
> > 
> > Is this about swapout to SSD only?
> 
> If you're using spinning rust with its limit of, what, 200 seeks per
> second, I'd suggest that swapout should also be limited but for
> different reasons.  We can set you up with a laptop with insufficient
> RAM and a 5400rpm drive if you'd like to be convinced ...

^_^

Yeah, we don't enable disk swap on the hard drive hosts that are
left. This aspect is only about write endurance management on SSD
during proactive reclaim.