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[73.202.227.126]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2fcb8571586sm2111645a91.0.2025.02.20.15.51.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 20 Feb 2025 15:51:51 -0800 (PST) Message-ID: Date: Thu, 20 Feb 2025 15:51:50 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH rcu 1/9] rcu: Add lockdep_assert_in_rcu_read_lock() and friends To: paulmck@kernel.org Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, Jens Axboe , ath12k@lists.infradead.org References: <657595c8-e86c-4594-a5b1-3c64a8275607@paulmck-laptop> <20240604222355.2370768-1-paulmck@kernel.org> <9130e3da-1cc5-43ea-9153-47117d57caca@oss.qualcomm.com> <67063387-6ba9-47fe-b283-d6346da15d9a@paulmck-laptop> From: Jeff Johnson Content-Language: en-US In-Reply-To: <67063387-6ba9-47fe-b283-d6346da15d9a@paulmck-laptop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-ORIG-GUID: xMb7lW8RxZj7JMy8s7xg6C7djdxYtbiW X-Proofpoint-GUID: xMb7lW8RxZj7JMy8s7xg6C7djdxYtbiW X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-02-20_09,2025-02-20_02,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 clxscore=1015 bulkscore=0 phishscore=0 mlxlogscore=930 suspectscore=0 priorityscore=1501 mlxscore=0 spamscore=0 adultscore=0 malwarescore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2502100000 definitions=main-2502200158 On 2/20/2025 2:04 PM, Paul E. McKenney wrote: > On Thu, Feb 20, 2025 at 11:38:14AM -0800, Jeff Johnson wrote: >> On 6/4/24 15:23, Paul E. McKenney wrote: >>> There is no direct RCU counterpart to lockdep_assert_irqs_disabled() >>> and friends. Although it is possible to construct them, it would >>> be more convenient to have the following lockdep assertions: >>> >>> lockdep_assert_in_rcu_read_lock() >>> lockdep_assert_in_rcu_read_lock_bh() >>> lockdep_assert_in_rcu_read_lock_sched() >>> lockdep_assert_in_rcu_reader() >>> >>> This commit therefore creates them. >> >> I'm looking at some downstream code that is trying to become >> upstream compliant, and currently that code uses: >> >> RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "some message"); >> >> It seems like this would be a good use of one of these helper >> functions, but I'm shocked to see that no upstream code is using >> them yet. >> >> Is there a reason to not use these helpers? > > In cases where there is no additional useful information that can be > placed in "some message", the new helpers should be just fine. Thanks for the confirmation, Paul! /jeff