From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B2FF528EC for ; Wed, 14 May 2025 00:08:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747181325; cv=none; b=aq/BFUtwvtWtgH+byVyFWGZq0/TBVY3M/nu+pE7EJQ26fFIWsR201IF8i3YP5L1ZBHkwgvywkBRpDawI3E263MytwXHqURNtalkMjO5dGvRuvPk1m2QJxHQwR0lbg0tM6oHEXS7vl4HkSVYsfx57KM+zEGQXTEis/kjGL1WdpQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747181325; c=relaxed/simple; bh=e9+fJenbAzfMdlcaENqSvy+FdAmvx+hd0Heo749LyCI=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZcQ30fhHo3WcANr1v81g4Eyitm3jBIWCCfYQLaFCJR6ryoj0Ty1bHG/umJVaGPvNzpUM50rXOTC9dqIFGPx0FIvzUB1WO3GAGSIX4tDCXCTcS+VPmEjy3ijWmwGpqPhwoU5B2/FEzSMobhyrfhZu/JpYeyLmwl2RhbvideMjmas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TsPcjc+t; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TsPcjc+t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C23B8C4CEE4; Wed, 14 May 2025 00:08:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747181325; bh=e9+fJenbAzfMdlcaENqSvy+FdAmvx+hd0Heo749LyCI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TsPcjc+txOCVzBhJ2IpQrKDgBHP04eadfbOzZYBtBV6HNPMZ/VhThZ5IOMhiHjere +UuVsivVhe0ThNkg5eGH4AS9yjrCgQHyTCCyQmt8Csd1XDApgYefriZwpS1/dPFCVo xeDyUlVk3BYeYyX+SpjXL4cQLdhtVsVxJJgdOQQquTz2ma/ZvwdD2SIHS7kiLzt9QR qtMkBy3wEwEHAitG3PU/NyAH9ek5YEesTs3kgC3iKCLliXlMxvYsCJSPcIvq9lSv1C GRl8OPH9U+MSweHStcP+A1a3UbiXyD2a/dMS+Bac+HhEOVEjkHNcuQwfXc+pXGhfZT nIR9kMW2v9mcg== Date: Tue, 13 May 2025 17:08:44 -0700 From: Jakub Kicinski To: Samiullah Khawaja Cc: "David S . Miller " , Eric Dumazet , Paolo Abeni , almasrymina@google.com, willemb@google.com, jdamato@fastly.com, mkarsten@uwaterloo.ca, weiwan@google.com, netdev@vger.kernel.org Subject: Re: [PATCH net-next] net: stop napi kthreads when THREADED napi is disabled Message-ID: <20250513170844.03ef5752@kernel.org> In-Reply-To: <20250513002631.3155191-1-skhawaja@google.com> References: <20250513002631.3155191-1-skhawaja@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 13 May 2025 00:26:31 +0000 Samiullah Khawaja wrote: > @@ -7463,6 +7482,15 @@ static int napi_thread_wait(struct napi_struct *napi) > return 0; > } > > + /* Since the SCHED_THREADED is not set so we do not own this > + * napi and it is safe to stop here if we are asked to. Checking > + * the SCHED_THREADED before stopping here makes sure that this > + * napi was not schedule again while napi threaded was being > + * disabled. > + */ Not sure if this works: CPU 0 (IRQ) CPU 1 (NAPI thr) CPU 2 (config) ____napi_schedule() if (test_bit(NAPI_STATE_THREADED)) clear_bit(NAPI_STATE_THREADED) kthread_stop(thread) if (test_bit(NAPI_STATE_SCHED_THREADED)) .. if (kthread_should_stop()) exit set_bit(NAPI_STATE_SCHED_THREADED) wake_up_process(thread); > + if (kthread_should_stop()) > + break; > + > schedule(); > set_current_state(TASK_INTERRUPTIBLE);