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Tue, 27 Jul 2021 18:56:08 +0000 Subject: Re: [PATCH] x86/intel_rdt: use __this_cpu_read in pseudo_lock_fn() To: Hui Su , , , , , , , References: <20210723023342.3015-1-suhui@zeku.com> From: Reinette Chatre Message-ID: Date: Tue, 27 Jul 2021 11:56:04 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.12.0 In-Reply-To: <20210723023342.3015-1-suhui@zeku.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR04CA0306.namprd04.prod.outlook.com (2603:10b6:303:82::11) To BN0PR11MB5744.namprd11.prod.outlook.com (2603:10b6:408:166::16) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.219] (71.238.111.198) by MW4PR04CA0306.namprd04.prod.outlook.com (2603:10b6:303:82::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4352.29 via Frontend Transport; Tue, 27 Jul 2021 18:56:07 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: f5c2b8ea-db3d-479e-ec57-08d95130318e X-MS-TrafficTypeDiagnostic: BN9PR11MB5243: X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:3968; 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True ... but could you please elaborate what the issue is with using this_cpu_read()? It too is safe to use when interrupts are disabled. > > Signed-off-by: Hui Su > --- > arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c > index 2207916cae65..f0cc0a89333b 100644 > --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c > +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c > @@ -464,8 +464,8 @@ static int pseudo_lock_fn(void *_rdtgrp) > * cache. > */ > __wrmsr(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits, 0x0); > - closid_p = this_cpu_read(pqr_state.cur_closid); > - rmid_p = this_cpu_read(pqr_state.cur_rmid); > + closid_p = __this_cpu_read(pqr_state.cur_closid); > + rmid_p = __this_cpu_read(pqr_state.cur_rmid); > mem_r = plr->kmem; > size = plr->size; > line_size = plr->line_size; > Reinette