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Wed, 05 Aug 2026 00:30:54 -0700 (PDT) Received: from google.com ([2a00:79e0:2031:6:8002:2a47:a704:5a58]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-38fee066b9fsm3665743a91.17.2026.08.05.00.30.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Aug 2026 00:30:53 -0700 (PDT) Date: Wed, 5 Aug 2026 16:30:49 +0900 From: Sergey Senozhatsky To: "Barry Song (Xiaomi)" Cc: senozhatsky@chromium.org, akpm@linux-foundation.org, bigeasy@linutronix.de, hdanton@sina.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, minchan@kernel.org, ryncsn@gmail.com, yosry.ahmed@linux.dev, surenb@google.com, Dongdong Zhang Subject: Re: [RFC PATCH] zram: avoid preemption with CPU-based compression backends Message-ID: References: <20260805005545.66112-1-baohua@kernel.org> 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: <20260805005545.66112-1-baohua@kernel.org> On (26/08/05 08:55), Barry Song (Xiaomi) wrote: > @@ -128,14 +128,20 @@ struct zcomp_strm *zcomp_stream_get(struct zcomp *comp) > * so then unlock and re-try on the current CPU. > */ > mutex_lock(&zstrm->lock); > + if (!comp->ops->async && !IS_ENABLED(CONFIG_PREEMPT_RT)) > + preempt_disable(); We take slot_lock(), which is preemptible, under stream lock on some paths. > if (likely(zstrm->buffer)) > return zstrm; > mutex_unlock(&zstrm->lock); > } > }