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Fri, 13 Mar 2026 08:32:39 +0000 (GMT) Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Fri, 13 Mar 2026 09:32:39 +0100 From: Harald Freudenberger To: lirongqing Cc: Holger Dengler , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org Subject: Re: [PATCH] s390/pkey: Remove synchronize_rcu from pkey_handler_register Reply-To: freude@linux.ibm.com Mail-Reply-To: freude@linux.ibm.com In-Reply-To: <20260313052312.2389-1-lirongqing@baidu.com> References: <20260313052312.2389-1-lirongqing@baidu.com> Message-ID: <058c161c4e82d2d78ddb9c52cfc8ee50@linux.ibm.com> X-Sender: freude@linux.ibm.com Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: NbikojqJ0zWpLvjKPymhLbikpdNBnKU0 X-Authority-Analysis: v=2.4 cv=E6/AZKdl c=1 sm=1 tr=0 ts=69b3cbaa cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=kj9zAlcOel0A:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=zuLzuavZAAAA:8 a=VnNF1IyMAAAA:8 a=lFT4GuY0HqRxgGrVVpkA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzEzMDA2NSBTYWx0ZWRfX3eGf6MohNInO Hs4n8qj2JiYXKrUkZM643NghMg6bmFztdncq/1pNEIe1mxoOSjlaZEA5wZt7kR5jDiBIkz5br9c aCijDu3G/BuNNvOecAX89lDoZbDSK3fFLvdPHSkSeUaXa/rrexW2tQJwTD5rMZOFDQNhHcq+hxO fc1Jir96IIN/SnW78pp07aojUZ9GFCF/VfIkr6qRjZirQT9bY4W3mcN8lYSfUHk6Zai7KYqDFED REpYYbYEiVj1nGk6ylYf9H46ToiGx3LWMHwQpsEId3K5O55n+U7Rtp53/uCTvTwhBocXAFk+UOY +KTqPsXBcNNs+QBKj4KWnQF5NyxAh3tcyA7a+5KJbmXD6TIDJpdVPeNZfXNJycSTjDnsmBEoBwt U/tZcITTJ0Nn9uLFXy1D+YxdGiX6K1raj/Kuyg8LuVt6sFsjPh/OImls/IClt/HkwYDgeYoiPLX 8FpzrzlD4oI8J01G5eg== X-Proofpoint-ORIG-GUID: NbikojqJ0zWpLvjKPymhLbikpdNBnKU0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-03-13_01,2026-03-12_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 clxscore=1011 malwarescore=0 phishscore=0 suspectscore=0 priorityscore=1501 spamscore=0 lowpriorityscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603130065 On 2026-03-13 06:23, lirongqing wrote: > From: Li RongQing > > The synchronize_rcu() call after adding a handler to the handler_list > is redundant because RCU readers will either see the old list or the > new list. Removing this synchronization point reduces the blocking > time during handler registration. > > Signed-off-by: Li RongQing > --- > drivers/s390/crypto/pkey_base.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/s390/crypto/pkey_base.c > b/drivers/s390/crypto/pkey_base.c > index d60cd98..c2e29d6 100644 > --- a/drivers/s390/crypto/pkey_base.c > +++ b/drivers/s390/crypto/pkey_base.c > @@ -60,7 +60,6 @@ int pkey_handler_register(struct pkey_handler > *handler) > > list_add_rcu(&handler->list, &handler_list); > spin_unlock(&handler_list_write_lock); > - synchronize_rcu(); > > module_put(handler->module); Thanks Li RongQing Reviewed-by: Harald Freudenberger @Heiko/@Vasily/@Alexander will you pick this?