Messages in this thread | | | Date | Wed, 8 Oct 2008 13:02:43 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH, v3] shmat: introduce flag SHM_MAP_NOT_FIXED |
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On Wed, Oct 08, 2008 at 11:20:37AM +0100, Alan Cox wrote: > > That is racy when multi threaded because shmat() doesn't replace, so you > > would need to munmap() inbetween and someone else could steal the area > > then. Yes you could stick a loop around it. It could livelock. > > No, it's not a good interface I would advocate. > > You could just use pthread mutexes in your application. The rôle of the
malloc() can call mmap, so that would require putting a mutex around each malloc(). Good luck finding them all.
> kernel is not to provide nappies for people who think programming is too > hard but to provide services that can be used to build applications.
Outsourcing kernel locking to user space is not the way to go.
-Andi
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