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Tue, 2 Jun 2026 11:40:09 +0000 (GMT) Date: Tue, 2 Jun 2026 13:40:07 +0200 From: Alexander Gordeev To: Heiko Carstens Cc: Sven Schnelle , Vasily Gorbik , Christian Borntraeger , Juergen Christ , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [PATCH v5 6/7] s390/percpu: Provide arch_this_cpu_read() implementation Message-ID: <17c282b9-a74c-4d6c-a301-23bcc98d63b8-agordeev@linux.ibm.com> References: <20260526055702.1429061-1-hca@linux.ibm.com> <20260526055702.1429061-7-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260526055702.1429061-7-hca@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNjAyMDExMSBTYWx0ZWRfXxvi1KQ1CDv0i NCLN8luDhkGok2RiN/Et9d6nFWPvA4ezjTxO4to5iVgbYRAzdXtVMFSrv9SJj9nvWnssAAU0J+S PpnMnrrhOeKu4Big2wh4MRyVTXN9ShX3hEfF+mmEI7A6oXqTZmwCD3HcKmThZCfF58tgYGWWbiz GFgZz7GJ5AUwVSKHoOTkyxQUXyVATz0McWscL8k+HylJY9YjASD8USoAYYbhUH/Yyelc8Hg4nmy b/ZvNYYZG3rIrwder85SmwIU2aEiZ59s9U04yDWz+1PiZ7Tj2Npf+o7mzkEoJiQ3vqeuZktVjxH d/T1iMf2yIswnVMMn0eIegn9gx8Fo24nPDbbIaRPudiIfPShf3Hwr/NP6O6ICDSo/v5ZGWKuGta 0kqtN490ChxGcNMCDxg4EXCHnOQ/WndPhLBuuRFY8CtqwiUdxOCPOsLMGd9RNXB44bNjRO3ML6q CNRy7mrGVWdELjgxRQQ== X-Proofpoint-ORIG-GUID: p-GYYhKF6w0bmJgmeNk2nTMmHieVZ7j9 X-Authority-Analysis: v=2.4 cv=cOzQdFeN c=1 sm=1 tr=0 ts=6a1ec11e cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=kj9zAlcOel0A:10 a=FelO9ux0wxsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=VnNF1IyMAAAA:8 a=cgPm772acQ0nl-z8f2EA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-GUID: p-GYYhKF6w0bmJgmeNk2nTMmHieVZ7j9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-06-02_01,2026-05-28_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 impostorscore=0 lowpriorityscore=0 spamscore=0 bulkscore=0 malwarescore=0 phishscore=0 suspectscore=0 priorityscore=1501 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2605210000 definitions=main-2606020111 On Tue, May 26, 2026 at 07:57:01AM +0200, Heiko Carstens wrote: > Provide an s390 specific implementation of arch_this_cpu_read() instead > of the generic variant. The generic variant uses preempt_disable() / > preempt_enable() pair and READ_ONCE(). > > Get rid of the preempt_disable() / preempt_enable() pairs by providing an > own variant which makes use of the new percpu code section infrastructure. > > With this the text size of the kernel image is reduced by ~1k > (defconfig). Also 87 generated preempt_schedule_notrace() function > calls within the kernel image (modules not counted) are removed. > > Signed-off-by: Heiko Carstens > --- > arch/s390/include/asm/percpu.h | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) Acked-by: Alexander Gordeev