On Tue, Sep 24, 2013 at 12:50:45PM -0700, Boris Ostrovsky wrote: > On 09/12/2013 10:47 PM, Steven Rostedt wrote: > >On Thu, 12 Sep 2013 22:29:44 -0400 > >Boris Ostrovsky <boris.ostrov...@oracle.com> wrote: > > > >>From: Konrad Rzeszutek Wilk <konrad.w...@oracle.com> > >> > >>xen_init_spinlocks() currently calls static_key_slow_inc() before > >>jump_label_init() is invoked. When CONFIG_JUMP_LABEL is set (which usually > >>is > >>the case) the effect of this static_key_slow_inc() is deferred until after > >>jump_label_init(). This is different from when CONFIG_JUMP_LABEL is not > >>set, in > >>which case the key is set immediately. Thus, depending on the value of > >>config > >>option, we may observe different behavior. > >> > >>In addition, when we come to __jump_label_transform() from > >>jump_label_init(), > >>the key (paravirt_ticketlocks_enabled) is already enabled. On processors > >>where > >>ideal_nop is not the same as default_nop this will cause a BUG() since it is > >>expected that before a key is enabled the latter is replaced by the former > >>during initialization. > >> > >>To address this problem we need to move > >>static_key_slow_inc(¶virt_ticketlocks_enabled) so that it is called > >>after jump_label_init(). We also need to make sure that this is done before > >>other cpus start to boot. early_initcall appears to be a good place to do > >>so. > >>(Note that we cannot move whole xen_init_spinlocks() there since pv_lock_ops > >>need to be set before alternative_instructions() runs.) > >> > >Reviewed-by: Steven Rostedt <rost...@goodmis.org> > > > >Peter, > > > >This fixes a regression in 3.12 against xen. Please pull and push to > >Linus sometime soon. > > Peter, > > Are you planning on taking this patch?
If he hasn't done yet (and I don't see a tip-bot email so I think the answer is no) I can do it (as I am back from my mini vacation). Thanks for the ping! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
