Re: [PATCH v21 4/4] perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)
From: Rob Herring <robh@kernel.org>
Date: 2025-05-20 22:22:19
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On Mon, May 19, 2025 at 4:59 PM Rob Herring [off-list ref] wrote:
On Mon, May 19, 2025 at 04:06:22PM +0100, Will Deacon wrote:quoted
Hey Rob, On Mon, Apr 07, 2025 at 12:41:33PM -0500, Rob Herring (Arm) wrote:quoted
From: Anshuman Khandual <redacted> The ARMv9.2 architecture introduces the optional Branch Record Buffer Extension (BRBE), which records information about branches as they are executed into set of branch record registers. BRBE is similar to x86's Last Branch Record (LBR) and PowerPC's Branch History Rolling Buffer (BHRB).Since you picked this up from v19, the driver has changed considerably and I presume you will be continuing to extend it in future as the architecture progresses. Perhaps having you listed as Author (and crucially, in git blame :p) with Anshuman as a Co-developed-by: would be more appropriate?Shrug.
I did a comparison to v18 arm_brbe.c. It was 1134 lines. I (and Mark) have removed 332 lines and changed 369 lines. So a little more than half remains, but the unchanged parts are a lot of 1 line helper functions, brackets and whitespace. So given the more complex parts have changed, I will change the authorship. Rob