From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaly Kuznetsov Subject: Re: [PATCH 2/2] x86/vdso: Add VCLOCK_HVCLOCK vDSO clock read method Date: Fri, 10 Feb 2017 13:25:36 +0100 Message-ID: <87d1eqqlkv.fsf@vitty.brq.redhat.com> References: <20170209141052.18694-1-vkuznets@redhat.com> <20170209141052.18694-3-vkuznets@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: (Stephen Hemminger's message of "Thu, 9 Feb 2017 18:27:27 +0000") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Stephen Hemminger Cc: Haiyang Zhang , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Andy Lutomirski , Ingo Molnar , "H. Peter Anvin" , "devel@linuxdriverproject.org" , Thomas Gleixner , "virtualization@lists.linux-foundation.org" List-Id: virtualization@lists.linuxfoundation.org Stephen Hemminger writes: > Why not use existing seqlock's? > To be honest I don't quite understand how we could use it -- the sequence locking here is done against the page updated by the hypersior, we're not creating new structures (so I don't understand how we could use struct seqcount which we don't have) but I may be misunderstanding something. BTW, I just occured to me that I should've probably put the TSC reading code to mshyperv.h and use it from both vDSO and read_hv_clock_tsc() -- what do you thing? [snip] -- Vitaly