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

[Mi, Dapeng]

On 2/26/2025 5:46 PM, Peter Zijlstra wrote:
> On Wed, Feb 26, 2025 at 01:48:52PM +0800, Mi, Dapeng wrote:
>> On 2/25/2025 7:18 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.
>>> Not loving how this patch obscures the whole DS area thing and naming.
>> arch-PEBS uses a totally independent buffer to save the PEBS records and
>> don't use the debug store area anymore. To reuse the original function as
>> much as possible and don't mislead users to think arch-PEBS has some
>> relationship with debug store, the original key word "ds" in the function
>> names are changed to "BTS_PEBS". I know the name maybe not perfect, do you
>> have any suggestion? Thanks.
> Right, so I realize it has a new buffer, but why do you need to make it
> all complicated like this?
>
> Just leave the existing stuff and stick the new arch pebs buffer
> somewhere new. All that reserve nonsense shouldn't be needed anymore.
>
> Just add it to the intel_pmu_cpu_{prepare,starting,dying,dead} things.

Sure. would do.