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b=mjELq810kQ5D3q3weLTxrIDITwSR9lVGhB70yVb6+79saip8Aowfd5waqDTTOvbyXPx4yw/pVenAwNt0XRY0Uo4UnBeS//myc2jKwiAmqLCVE68GQwAdGvySUlwbeA+ZzZ8zaMXlqJJZxnZvANT6ev4IYJk6BZsUgIhxiVgEpX8= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from MW3PR12MB4553.namprd12.prod.outlook.com (2603:10b6:303:2c::19) by CH2PR12MB4293.namprd12.prod.outlook.com (2603:10b6:610:7e::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7897.17; Wed, 21 Aug 2024 18:08:43 +0000 Received: from MW3PR12MB4553.namprd12.prod.outlook.com ([fe80::b0ef:2936:fec1:3a87]) by MW3PR12MB4553.namprd12.prod.outlook.com ([fe80::b0ef:2936:fec1:3a87%6]) with mapi id 15.20.7897.014; Wed, 21 Aug 2024 18:08:43 +0000 Message-ID: <8b23eade-9015-4d40-b9f9-f7cf5a9d08c6@amd.com> Date: Wed, 21 Aug 2024 13:08:38 -0500 User-Agent: Mozilla Thunderbird Reply-To: babu.moger@amd.com Subject: Re: [PATCH v6 19/22] x86/resctrl: Introduce the interface to switch between monitor modes To: Reinette Chatre , corbet@lwn.net, fenghua.yu@intel.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com Cc: x86@kernel.org, hpa@zytor.com, paulmck@kernel.org, rdunlap@infradead.org, tj@kernel.org, peterz@infradead.org, yanjiewtw@gmail.com, kim.phillips@amd.com, lukas.bulwahn@gmail.com, seanjc@google.com, jmattson@google.com, leitao@debian.org, jpoimboe@kernel.org, rick.p.edgecombe@intel.com, kirill.shutemov@linux.intel.com, jithu.joseph@intel.com, kai.huang@intel.com, kan.liang@linux.intel.com, daniel.sneddon@linux.intel.com, pbonzini@redhat.com, sandipan.das@amd.com, ilpo.jarvinen@linux.intel.com, peternewman@google.com, maciej.wieczor-retman@intel.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, eranian@google.com, james.morse@arm.com References: <784eaa900b9e0778ddc534c04c7ded9466bfd19b.1722981659.git.babu.moger@amd.com> Content-Language: en-US From: "Moger, Babu" In-Reply-To: Content-Type: text/plain; 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> > This needs to be protected by the mutex. Agree.. Will do. > >> +    struct rdt_resource *r = of->kn->parent->priv; >> +    int ret = 0; >> + >> +    /* Valid input requires a trailing newline */ >> +    if (nbytes == 0 || buf[nbytes - 1] != '\n') >> +        return -EINVAL; >> + >> +    buf[nbytes - 1] = '\0'; >> + >> +    cpus_read_lock(); >> +    mutex_lock(&rdtgroup_mutex); >> + >> +    rdt_last_cmd_clear(); >> + >> +    if (!strcmp(buf, "legacy")) { >> +        if (mbm_cntr_assign) >> +            resctrl_arch_mbm_cntr_assign_disable(); >> +    } else if (!strcmp(buf, "mbm_cntr_assign")) { >> +        if (!mbm_cntr_assign) { >> +            rdtgroup_mbm_cntr_reset(r); >> +            ret = resctrl_arch_mbm_cntr_assign_enable(); >> +        } >> +    } else { >> +        ret = -EINVAL; >> +    } >> + >> +    mutex_unlock(&rdtgroup_mutex); >> +    cpus_read_unlock(); >> + >> +    return ret ?: nbytes; >> +} >> + > > Reinette > -- Thanks Babu Moger