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Fri, 13 Nov 2026 08:23:51 -0800 (PST) Received: from fedora ([2a02:168:fe54:0:500c:846b:8abe:fa7a]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4bb55ac1159sm65716205e9.4.2026.11.13.08.23.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Nov 2026 08:23:50 -0800 (PST) From: Cinq Prairie To: Jens Axboe Cc: Jakub Kicinski , Stefan Roesch , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] io_uring/napi: don't end the single NAPI busy poll early on need_resched() Date: Fri, 13 Nov 2026 17:23:47 +0100 Message-ID: <20261113162347.5617-1-notprairie@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <179426098226.155418.4382559329615606121.b4-ty@b4> References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, 09 Nov 2026 14:49:42 -0700, Jens Axboe wrote: > Applied, thanks! > > [1/1] io_uring/napi: don't end the single NAPI busy poll early on need_resched() > commit: 39c7210e970200f8b17de3767c73efe64173a95f Thanks. On the cond_resched() follow-up: I no longer think it is worth sending. Since 7dadeaa6e851 ("sched: Further restrict the preemption modes") in v7.0, PREEMPT_NONE/PREEMPT_VOLUNTARY can't be selected on archs with lazy preemption (x86, arm64, ...), so CONFIG_PREEMPTION is always set there and cond_resched() compiles to a no-op. On those kernels the need_resched() break in __napi_busy_loop() is already followed by a preempt_enable() that reschedules, so a yield between laps wouldn't add anything but a dead cond_resched() call while they are actively being removed tree-wide. Unless you'd like it for the few architectures still able to build PREEMPT_VOLUNTARY, I'll leave it there.