Subject: Re: linux-next: add utrace tree

From: Andi Kleen <[email-masked]>
Date: Tue, 26 Jan 2010 18:33:26 +0100

Tom Tromey <[email-masked]> writes:

> * Use an fd, not SIGCHLD+wait, to report inferior state changes to gdb.
>   Internally we're already using a self-pipe to integrate this into
>   gdb's main loop.  Relatedly, don't mess with the inferior's parentage.

How would having a kernel based solution be better over your
user space simulation?

BTW there's the new signalfd() system call that might do it
(haven't checked if it works for SIGCHLD)

> * Support "displaced stepping" in the kernel; I think this would improve
>   performance when debugging in non-stop mode.

Not sure what "displaced stepping" is exactly, but it 
sounds like the branch tracing extensions that got added a 
few releases ago? On modern Intel chips they give you a branch
buffer in memory.

-Andi
-- 
[email-masked] -- Speaking for myself only.