Re: [RFC PATCH 0/8] accel/tcg: cut per-block dispatch overhead

On 8/18/26 10:42, Matt Turner wrote:
>    4  RFC: tcg: probe the TB jump cache inline instead of calling a helper
> 
>       95.8% of those 8.4 billion helper_lookup_tb_ptr() calls hit the jump
>       cache. Emit the probe inline (hash, three guarded loads, goto_ptr)
>       and call the helper only on a miss.               -36.51%, -27.05% wall
> 
>    5  RFC: accel/tcg: allow cross-page goto_tb chaining in user-only builds
> 
>       translator_use_goto_tb() refuses to chain across a page. In user-only
>       builds the invalidation path already covers what that was protecting
>       against: every mmap/mprotect/munmap reaches page_set_flags(), which
>       invalidates and unlinks. Lift it there, keep it for system mode.
>                                                          -2.42%, -4.68% wall

Both of these will break breakpoints.

However: for user-only, gdb can only be attached at startup.  So we can recognize that no 
breakpoints are possible and make this optimization then.


r~