On 12/01/2026 2:43 pm, Jan Beulich wrote: > On 12.01.2026 15:08, Alejandro Vallejo wrote: >> Debug builds stress the wrapping logic of the TLB clock by narrowing it >> down to 10 bits. This is inconvenient to test real time workloads on >> such builds. >> >> Add Kconfig option to be able to selectively use the non-stressed >> behaviour on debug. >> >> Signed-off-by: Alejandro Vallejo <[email protected]> > Hmm, yes, why not. However, ... > >> --- a/xen/arch/x86/flushtlb.c >> +++ b/xen/arch/x86/flushtlb.c >> @@ -20,11 +20,7 @@ >> #include <asm/spec_ctrl.h> >> >> /* Debug builds: Wrap frequently to stress-test the wrap logic. */ >> -#ifdef NDEBUG >> -#define WRAP_MASK (0xFFFFFFFFU) >> -#else >> -#define WRAP_MASK (0x000003FFU) >> -#endif >> +#define WRAP_MASK (IS_ENABLED(CONFIG_DEBUG_TLB_CLK) ? 0x3FFU : UINT32_MAX) > ... the comment then will want updating as well, I'd say. It doesn't go > terribly stale this way, but at least slightly. I'd suggest to minimally > drop "builds".
I'm suggest just dropping WRAP_MASK. We've done this locally in the XenServer patchqueue since 2011 or so due to the overhead, and I don't think it's interesting enough to warrant a separate option. ~Andrew
