Messages in this thread | | | Date | Mon, 23 Aug 2010 18:18:07 +0100 | Subject | Re: [RFC] mlock/stack guard interaction fixup | From | Ian Jackson <> |
| |
Peter Zijlstra writes ("Re: [RFC] mlock/stack guard interaction fixup"): > On Mon, 2010-08-23 at 16:42 +0100, ijackson@chiark.greenend.org.uk > wrote: > > mlocking the stack is entirely sensible and normal for a real-time > > program. Most such programs use mlockall but there is no particular > > reason why a program that has some more specific requirements should > > use mlock to lock only a part of the stack. (Perhaps it has only one > > real-time thread?) > > RT apps should pre-allocate and mlock their stack in advance (and > pre-fault too for the paranoid).
Are you allowed to mlock a stack page which has not yet been faulted in ? What effect does it have ? I wasn't able to find a convincing de jure answer to this question.
But you seem, like me, to be disagreeing with Linus's assertion that calling mlock() on the stack is something no sane programs does ?
> mlockall is a very bad interface and should really not be used.
You are directly contradicting the advice in SuS, to which I just gave a reference. You're free to do so of course but it might be worth explaining in a bit more detail why the advice in SuS is wrong.
Ian.
| |