On 5/2/2025 1:52 AM, Ingo Molnar wrote:

* Xin Li (Intel) [off-list ref] wrote:

quoted

For some reason, there are some TSC-related functions in the MSR
header even though there is a tsc.h header.

Relocate rdtsc{,_ordered}() from <asm/msr.h> to <asm/tsc.h>, and
subsequently remove the inclusion of <asm/msr.h> in <asm/tsc.h>.

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

quoted

--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h

@@ -7,7 +7,81 @@
  
  #include <asm/cpufeature.h>
  #include <asm/processor.h>
-#include <asm/msr.h>

Note that in the tip:x86/msr commit I've applied today I've
intentionally delayed the removal of this header dependency, to reduce
the probability of breaking -next today or in the near future.

We can remove that now superfluous header dependency in a future patch.

This is truly a brilliant decision!

Especially regarding the issues Ilpo identified.

Thanks!
     Xin