lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 8 Aug 2014 12:10:55 -0400 From: Steven Rostedt <rostedt@...dmis.org> To: Peter Zijlstra <peterz@...radead.org> Cc: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>, Oleg Nesterov <oleg@...hat.com>, linux-kernel@...r.kernel.org, mingo@...nel.org, laijs@...fujitsu.com, dipankar@...ibm.com, akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com, josh@...htriplett.org, tglx@...utronix.de, dhowells@...hat.com, edumazet@...gle.com, dvhart@...ux.intel.com, fweisbec@...il.com, bobby.prani@...il.com, masami.hiramatsu.pt@...achi.com Subject: Re: [PATCH v3 tip/core/rcu 3/9] rcu: Add synchronous grace-period waiting for RCU-tasks On Fri, 8 Aug 2014 18:01:28 +0200 Peter Zijlstra <peterz@...radead.org> wrote: > Well, see the _BIG_ difference is that currently, when I do nop > > current_tracer all that memory is instantly freed again. > > With the proposed scheme, if I setup state, reconsider, destroy state, > try again, and generally muck about I can tie up unspecified amounts of > memory. > > And being the bumbling idiot that I am, that's actually fairly typical > of how I end up tracing. There's no neat and tidy, I trace something, > look at the trace, script a little, muck about with the settings and > goto 1. It would actually be trivial to make that case never free the trampoline associated to function tracing. As that is a static ops that never gets freed, the trampoline it uses doesn't need to be freed either. But, if you were to do: # cd /sys/kernel/debug/tracing # mkdir instances/foo # cd instances/foo 1: # echo function > current_tracer # echo nop > current_tracer goto 1 Then, yeah that could do it. > > > In any case, I think I now fully understand what you're trying to do, > just not sure its all win. Fair enough. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists