Re: [PATCH v4 2/2] timer: allow platform to override cpu TSC frequency

2024-10-03 Thread Isaac Boukris
On Thu, Oct 3, 2024 at 12:31 PM Bruce Richardson wrote: > > On Wed, Oct 02, 2024 at 10:14:57PM +0300, Isaac Boukris wrote: > > On Wed, Oct 2, 2024 at 8:11 PM Bruce Richardson > > wrote: > > > > > > On Wed, Oct 02, 2024 at 07:56:36PM +0300, Isaac Boukris wrote: > > > > The CPU value is often not a

Re: [PATCH v4 2/2] timer: allow platform to override cpu TSC frequency

2024-10-03 Thread Bruce Richardson
On Wed, Oct 02, 2024 at 10:14:57PM +0300, Isaac Boukris wrote: > On Wed, Oct 2, 2024 at 8:11 PM Bruce Richardson > wrote: > > > > On Wed, Oct 02, 2024 at 07:56:36PM +0300, Isaac Boukris wrote: > > > The CPU value is often not accurate, allow overriding it based > > > on info from the host OS. > >

Re: [PATCH v4 2/2] timer: allow platform to override cpu TSC frequency

2024-10-02 Thread Isaac Boukris
On Wed, Oct 2, 2024 at 8:11 PM Bruce Richardson wrote: > > On Wed, Oct 02, 2024 at 07:56:36PM +0300, Isaac Boukris wrote: > > The CPU value is often not accurate, allow overriding it based > > on info from the host OS. > > > > On Linux X86, if the tsc_known_freq cpu flag is missing, it means > > t

Re: [PATCH v4 2/2] timer: allow platform to override cpu TSC frequency

2024-10-02 Thread Bruce Richardson
On Wed, Oct 02, 2024 at 07:56:36PM +0300, Isaac Boukris wrote: > The CPU value is often not accurate, allow overriding it based > on info from the host OS. > > On Linux X86, if the tsc_known_freq cpu flag is missing, it means > the kernel doesn't trust it and calculates its own. We should do > the

[PATCH v4 2/2] timer: allow platform to override cpu TSC frequency

2024-10-02 Thread Isaac Boukris
The CPU value is often not accurate, allow overriding it based on info from the host OS. On Linux X86, if the tsc_known_freq cpu flag is missing, it means the kernel doesn't trust it and calculates its own. We should do the same to avoid drift. On freebsd we have access to the kernel tsc_hz value