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b=mz4GMpfDr84Fj0UJvxn1bpFSiBraixonk9d0naNaahLGl+2J3bRwuNNw5G9p1qSSz mksxu8SA/YWpL74R601ohIj4y5vp3EWdNwb4LM8m1HQJouxYbFsFCOYuxUDS6YtkhR eeFVUZnH+jDXQAWQ9buThneFp0DB4cw5GGHoR0F8Nd0rHBNXXmeN+jXaAfFwdE8tIm l8w0eSw+TmMkln0ZY0Zt84VP7ZwGWV/iyyq8PlYe0rEzusNf1WFQK2Ne3RTyhapr0K xvMU68ZdAXu2ORVtDiKR/urvKodbxjYjFUKAwf+NZEhS9ts5vNQNr6QU2t8sLJybEk C3p8UE+B8CMIQ== Date: Tue, 10 Jun 2025 13:33:05 -1000 From: Tejun Heo To: Shakeel Butt Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Vlastimil Babka , Alexei Starovoitov , Sebastian Andrzej Siewior , Michal =?iso-8859-1?Q?Koutn=FD?= , Harry Yoo , Yosry Ahmed , bpf@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team Subject: Re: [PATCH 2/3] cgroup: make css_rstat_updated nmi safe Message-ID: References: <20250609225611.3967338-1-shakeel.butt@linux.dev> <20250609225611.3967338-3-shakeel.butt@linux.dev> <35ppn2muk4bsyosca4nxnbv5l6qv4ov2cxg5ksypst5ldf5zc4@vwrpziws4wjy> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam01 X-Stat-Signature: dmsa9b7g3j57dxhp4sdxs7mfhbq5a74o X-Rspamd-Queue-Id: 6D6A14000B X-Rspam-User: X-HE-Tag: 1749598388-142612 X-HE-Meta: U2FsdGVkX1/Z96ftfHz0pfoyagZYTnCx2psXCK7+ct9Q6UNRIOo7KsPe0AHc+F+DVfHwPsn1Dxse0ze4WTlnfbp07Z03UIvyQ3u8m4LJKtTchs6feZkVQkGsuY0mjuE07/DrW8k5EvU+k8jvXkaXR0n9ZYKUJ2HKdI5G6GkD6lP5gMRcr/DuGaQQhFZESKTdlWzfi4ZOIL2nR+8BtYB9oCqLzDtUBmH4gxN+sG5nssegrOTnhS6ld9vBiEUIKhrLrGdJnE08MR9UfI7zOZW2bb7lxV2fX2u8Tkcsw09ZMutii+FJONU4rQclavlh9kQuWmFNrYw3bkvfv1Wd7tnpGXDfV13JLDLRS8zfaNB062zc+ZD8WCUE7lF2udtiHK+boY/XWwDKnMHW0GrZer1QWxn9pFNNZamLs7mmkVygd3LSDyu2f9cJI4tHcMwW9qk6ZWSarPV6Kazf9tYmt8Wix/xyX3z2JbaFf+vdL60kb2MQwdujKhn0HDTTmHVMwX0kTG7s3WOmel1WPVHyZ5zmeiG/0diUsQHoozYPEHYcf4O3wB5VL8WoT5loMMbw7D3HTb8/IjuhCP72gpOnFifklu+VZe3dZYnTnzTh16pS/K5WN8lNy4llt+zcATnV8gu1M/qzcrS57yOYhskpwCT+CC2glqV4dvv2Pp7A/aV/xbupHYqB7bOoe9AXH9N5sSd5lppHnDtlENrGQJGDH88CSq/TVLl5OwCzpH4QSBCnSefOiU863+tAh5Igr9Bbfc70div5y6SV1+uZLiL69sKgI8nXhj54IrYz9cOA7yU8GsJAChJUvWNjG67OXQruPxiCA2DkewAKxrLL+oLQaK5OYfLcP/bDGGQ6OJI5cGx80SeybpQasvstuoYwxj8rU/qHA4f0anfVNrBYoyxty5Yz76yPhY+gMcphpwTm/GLRX+PN/ikqTjDSX+fHUaXMT/+wQg2NkWHFXu4J4igm6iY mfuXgz35 Ey/dpDmwJ0Hl8CykUq9X+b7eU+11g9cSM6Fnb3yyEgOU8Ga80LLLMwLZEVeJnvHJBnWz9L3NkjqtTVcQiIVWId4TSvG4I2UbPH5iI7U5ATUwNiLMR+ADIUC0U+NyspkFsBTQyJ4b7/83Kts7JyjQPq/DjeHPOPiIpcyta6gIEOugmGm/4qRn4F0VimiYSmIHtI40BT9uHZlalalHWQJqekh0uXdZTtNk06hHHrimCqGllHejGAbBTLJwjUerH6EKf6+iyoH+zP76zr+Q= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello, On Tue, Jun 10, 2025 at 04:28:23PM -0700, Shakeel Butt wrote: ... > I was actually thinking of using this_cpu_cmpxchg but then I need to > also check for CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS. However if you > prefer that, I can try this_cpu_cmpxchg in the next version. Yeah, I don't think it'd make any performance differences, but, provided it doesn't too much complexity, it'd make things less confusing as the construct being used aligns with the problem being solved. Thanks. -- tejun