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Wed, 11 Mar 2026 20:05:10 -0700 (PDT) Received: from google.com ([2a00:79e0:2031:6:8bb8:36d7:daf6:bf85]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35a02fc8465sm3647444a91.9.2026.03.11.20.05.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Mar 2026 20:05:09 -0700 (PDT) Date: Thu, 12 Mar 2026 12:05:05 +0900 From: Sergey Senozhatsky To: Matt Fleming Cc: Andrew Morton , Jens Axboe , Minchan Kim , Sergey Senozhatsky , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@cloudflare.com, Matt Fleming Subject: Re: [RFC PATCH 0/1] mm: Reduce direct reclaim stalls with RAM-backed swap Message-ID: References: <20260303115358.1323188-1-matt@readmodwrite.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260303115358.1323188-1-matt@readmodwrite.com> On (26/03/03 11:53), Matt Fleming wrote: > What about mixed swap configurations (zram + disk)? > > When at least one disk-backed swap device is active, > swap_all_ram_backed is false and the current behaviour is preserved. > Per-device reclaimable accounting is possible but it's a much larger > change, and mixed zram+disk configurations are uncommon in practice > AFAIK. There are also setups where zram is configured with a backing device (a real physical device) to which zram writeback pages, effectively releasing pool memory that they occupied.