From: Andi Kleen <ak@suse.de>
To: renzo@cs.unibo.it (Renzo Davoli)
Cc: osd@cs.unibo.it, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] 2-ptrace_multi
Date: 18 May 2006 22:17:08 +0200 [thread overview]
Message-ID: <p73sln72im3.fsf@bragg.suse.de> (raw)
In-Reply-To: <20060518155848.GC17498@cs.unibo.it>
renzo@cs.unibo.it (Renzo Davoli) writes:
> ptmulti kernel patch inserts a new useful option for ptrace() call,
> adding a new request type to ptrace() syscall.
>
> With PTRACE_MULTI option you can send multiple ptrace requests with a
> single system call: commonly a process that uses ptrace() needs
> several PTRACE_PEEKDATA for getting some useful, even small pieces of data.
> It is useful for these programs to run several ptrace
> operations while limiting the number of context switches.
What context switches do you mean? System calls? Linux is in general
designed to have very cheap system calls and they shouldn't be more tha
a few hundred cycles.
>
> Debuggers and virtual machines (like User Mode Linux) and many other
> applications that are based on ptrace can get great
> performance improvements by PTRACE_MULTI: the number of system
> calls (and context switches) decreases significantly.
You forgot to add numbers?
-Andi
next prev parent reply other threads:[~2006-05-18 20:17 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-05-18 15:53 ptrace enhancements for VM support (patch proposals follow in sep.msgs) Renzo Davoli
2006-05-18 15:56 ` [PATCH] 1-access_process_vm_user Renzo Davoli
2006-05-18 15:58 ` [PATCH] 2-ptrace_multi Renzo Davoli
2006-05-18 20:17 ` Andi Kleen [this message]
2006-05-18 21:13 ` Renzo Davoli
2006-05-19 2:23 ` Ulrich Drepper
2006-05-19 9:07 ` Renzo Davoli
2006-05-19 13:09 ` Daniel Jacobowitz
2006-05-19 17:45 ` Renzo Davoli
2006-05-19 19:15 ` Renzo Davoli
2006-05-19 20:15 ` Daniel Jacobowitz
2006-05-19 20:17 ` Andi Kleen
2006-05-20 6:44 ` Ulrich Drepper
2006-05-20 14:37 ` Alan Cox
2006-05-20 18:30 ` Renzo Davoli
2006-05-20 20:23 ` Ulrich Drepper
2006-05-20 21:39 ` Jeff Dike
2006-05-21 12:38 ` Avi Kivity
2006-05-21 15:28 ` Renzo Davoli
2006-05-22 13:02 ` Daniel Jacobowitz
2006-05-22 15:05 ` Renzo Davoli
2006-05-22 15:26 ` Daniel Jacobowitz
2006-05-18 16:07 ` [PATCH] 3-ptrace_vm Renzo Davoli
2006-05-21 8:03 ` ptrace enhancements for VM support (patch proposals follow in sep.msgs) Peter Chubb
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