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([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id lu21sm730110ejb.31.2021.06.18.01.28.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 18 Jun 2021 01:28:47 -0700 (PDT) Subject: Re: [PATCH v11 2/7] KVM: stats: Add fd-based API to read binary stats data To: Greg KH , Jing Zhang Cc: KVM , KVMARM , LinuxMIPS , KVMPPC , LinuxS390 , Linuxkselftest , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Will Deacon , Huacai Chen , Aleksandar Markovic , Thomas Bogendoerfer , Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Peter Shier , Oliver Upton , David Rientjes , Emanuele Giuseppe Esposito , David Matlack , Ricardo Koller , Krish Sadhukhan , Fuad Tabba References: <20210618044819.3690166-1-jingzhangos@google.com> <20210618044819.3690166-3-jingzhangos@google.com> From: Paolo Bonzini Message-ID: Date: Fri, 18 Jun 2021 10:28:46 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On 18/06/21 08:57, Greg KH wrote: >> + * 2. Read descriptors from its offset and discover all the stats by parsing >> + * descriptors. This is a one-time work for the lifecycle of the >> + * corresponding vm/vcpu stats fd. >> + * 3. Periodically read stats data from its offset. > You forgot "2.5. rewind fd pointer position", see below... Or use pread (that's what the test does). I'll do a copy-editing pass and be sure to mention that as well. Paolo