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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-437c73e7140sm233769725e9.0.2025.01.21.00.50.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Jan 2025 00:50:46 -0800 (PST) Date: Tue, 21 Jan 2025 08:50:45 +0000 From: David Laight To: Dan Carpenter Cc: Jakub Kicinski , davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, jdamato@fastly.com, Francois Romieu , pcnet32@frontier.com, anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com, marcin.s.wojtas@gmail.com Subject: Re: [PATCH net-next v2 06/11] net: protect NAPI enablement with netdev_lock() Message-ID: <20250121085045.480c2e51@pumpkin> In-Reply-To: References: <20250115035319.559603-1-kuba@kernel.org> <20250115035319.559603-7-kuba@kernel.org> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) 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, 21 Jan 2025 11:32:24 +0300 Dan Carpenter wrote: > On Tue, Jan 14, 2025 at 07:53:14PM -0800, Jakub Kicinski wrote: > > Wrap napi_enable() / napi_disable() with netdev_lock(). > > Provide the "already locked" flavor of the API. > > > > iavf needs the usual adjustment. A number of drivers call > > napi_enable() under a spin lock, so they have to be modified > > to take netdev_lock() first, then spin lock then call > > napi_enable_locked(). > > You missed some. > > drivers/net/ethernet/broadcom/tg3.c:7427 tg3_napi_enable() warn: sleeping in atomic context > drivers/net/ethernet/nvidia/forcedeth.c:5597 nv_open() warn: sleeping in atomic context ... Looks like the whole patch is very fragile. You really need to keep the existing function names having their existing semantics. Add a new function, change all the code, then delete the old function. It also looks as though drivers will end up holding netdev_lock() for long periods just so they can do a napi_enable() much later on. David