On June 19, 2025 5:04:36 AM EDT, Peter Zijlstra [off-list ref] wrote:

On Thu, Jun 19, 2025 at 04:47:14AM -0400, Steven Rostedt wrote:

quoted

On Thu, 19 Jun 2025 09:56:11 +0200
Peter Zijlstra [off-list ref] wrote:

quoted

Well, the trivial solution is to make it 511 and call it a day. Don't
make things complicated if you don't have to.

I don't know if this is more complicated, but it should make it fit
nicely in a page:

  /* Make the cache fit in a page */
  #define UNWIND_MAX_ENTRIES                                      \
        ((PAGE_SIZE - sizeof(struct unwind_cache)) / sizeof(long))

Right, that's the fancy way of spelling 511 :-) Except on 32bit, where
it now spells 1023 instead.

Did you want that bitness difference?

Also, you ready for some *reaaally* big numbers on Power/ARM with 64K
pages? :-)

Bah, yeah, I need to use a size and not just PAGE_SIZE.

 Thanks,

-- Steve