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Thu, 07 May 2026 00:10:58 -0700 (PDT) Received: from [192.168.88.32] ([150.228.93.82]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-48e538aaa0fsm126515705e9.7.2026.05.07.00.10.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 07 May 2026 00:10:57 -0700 (PDT) Message-ID: Date: Thu, 7 May 2026 09:10:56 +0200 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net 01/12] net: shaper: drop redundant xa_lock() bracketing To: Jakub Kicinski Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, andrew+netdev@lunn.ch, horms@kernel.org, shuah@kernel.org, linux-kselftest@vger.kernel.org References: <20260506000628.1501691-1-kuba@kernel.org> <20260506000628.1501691-2-kuba@kernel.org> <20260506153348.1c278f4f@kernel.org> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20260506153348.1c278f4f@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/7/26 12:33 AM, Jakub Kicinski wrote: > On Wed, 6 May 2026 17:30:32 +0200 Paolo Abeni wrote: >> On 5/6/26 2:06 AM, Jakub Kicinski wrote: >>> The shaper insertion code is written in a way that suggests that >>> perhaps it was expecting readers to be fenced off by xa_lock. >> >> FTR, the code was shaped (pun intended :) that way to avoid acquiring >> multiple times the xa_lock when not needed. Sort of evil early optimization. > > Ah, that makes more sense, I guess. Do you prefer me to drop this patch? > The XA lock is guaranteed not to be contended since we're under the > netdev mutex.. Sorry, I should have been more clear: I'm fine with the patch, just giving more context, as far as I remembered it. /P