Re: [Patch v2 12/24] perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR

[Mi, Dapeng]

On 2/26/2025 5:48 PM, Peter Zijlstra wrote:
> On Wed, Feb 26, 2025 at 02:19:15PM +0800, Mi, Dapeng wrote:
>> On 2/25/2025 7:25 PM, Peter Zijlstra wrote:
>>> On Tue, Feb 18, 2025 at 03:28:06PM +0000, Dapeng Mi wrote:
>>>> Arch-PEBS introduces a new MSR IA32_PEBS_BASE to store the arch-PEBS
>>>> buffer physical address. This patch allocates arch-PEBS buffer and then
>>>> initialize IA32_PEBS_BASE MSR with the buffer physical address.
>>> Just to clarify, parts with ARCH PEBS will not have BTS and thus not
>>> have DS?
>> No, DS and BTS still exist along with arch-PEBS, only the legacy DS based
>> PEBS is unavailable and replaced by arch-PEBS.
> Joy. Is anybody still using BTS now that we have PT? I thought PT was
> supposed to be the better BTS.

Yeah, I suppose no one still use BTS, but suppose it would need a long time
to drop BTS on HW.