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Wed, 14 Oct 2026 19:04:07 -0700 (PDT) Received: from google.com ([2a00:79e0:2031:6:8455:7899:5a2e:26f8]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ac94748c6csm1889088a91.10.2026.10.14.19.04.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Oct 2026 19:04:06 -0700 (PDT) Date: Thu, 15 Oct 2026 11:04:03 +0900 From: Sergey Senozhatsky To: Barry Song Cc: Bo Zhang , senozhatsky@chromium.org, akpm@linux-foundation.org, bgeffon@google.com, minchan@kernel.org, richardycc@google.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 10/11] zram: use rw_semaphore for decompression streams Message-ID: References: <20261013035201.2809924-11-senozhatsky@chromium.org> <20261014153603.1365617-1-zhangbo56@xiaomi.com> Precedence: bulk X-Mailing-List: linux-block@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: On (26/10/15 04:46), Barry Song wrote: > Also, with either deflate or zstd, create_dctx() will > always be present. So, what algorithm are we actually testing? > What happens if we switch to zstd? Right. Am not that concerned with deflate, but seeing zstd on that list is a tad sad. zstd mutates decompression ctx, so it cannot be shared. On the other hand, zstd_dctx_workspace_bound() is almost 100KB so allocating dctx per-read request will be rather problematic.