On 09/04, Hugh Dickins wrote: > > On Thu, 4 Sep 2014, Oleg Nesterov wrote: > > On 09/04, Peter Zijlstra wrote: > > > On Wed, Sep 03, 2014 at 06:08:19PM +0200, Oleg Nesterov wrote: > > > > > > > And a stupid (really, I don't understand this code) question: > > > > > > > > /* for example, ksmd faulting in a user's mm */ > > > > if (!p->mm) > > > > return; > > I don't understand your difficulty with that, I thought the comment > was helpful enough.
Yes, yes, sorry for confusion, the comment and the check itself look clear. > Does the original commit comment help? > > commit 2832bc19f6668fd00116f61f821105040599ef8b > Author: Hugh Dickins <[email protected]> > Date: Wed Dec 19 17:42:16 2012 -0800 > > sched: numa: ksm: fix oops in task_numa_placment() > > task_numa_placement() oopsed on NULL p->mm Yes. But I thought that even if task_numa_placment() didn't OOPS in case when ->mm = NULL, it would be better to exclude ksmd. And other kthreads which can have ->mm != NULL, and PTRACE_POKE or sys_process_vm_writev() users: /* do nothing if this task accesses a foreign mm */ if (p->mm != mm || (p->flags & PF_KTHREAD) return; Please forget. This is minor, and my main question was the wrong usage of TASK_DEAD. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
