Since sequence count algorithm is done by hypervisor, better to not reuse seqcount. Still concerned that the code is racy.
-----Original Message----- From: Thomas Gleixner [mailto:[email protected]] Sent: Friday, February 10, 2017 4:28 AM To: Vitaly Kuznetsov <[email protected]> Cc: Stephen Hemminger <[email protected]>; [email protected]; Andy Lutomirski <[email protected]>; Ingo Molnar <[email protected]>; H. Peter Anvin <[email protected]>; KY Srinivasan <[email protected]>; Haiyang Zhang <[email protected]>; Dexuan Cui <[email protected]>; [email protected]; [email protected]; [email protected] Subject: Re: [PATCH 2/2] x86/vdso: Add VCLOCK_HVCLOCK vDSO clock read method On Fri, 10 Feb 2017, Vitaly Kuznetsov wrote: > Stephen Hemminger <[email protected]> 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. You can't use seqlock, but you might be able to use seqcount. Though I doubt it given the 0 check .... Thanks, tglx _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
