[Devel] [PATCH rh7 02/11] ub: zap show_ub_mem

[Vladimir Davydov]

On Sat, May 23, 2015 at 09:10:21AM +0300, Vasily Averin wrote:
> 
> 
> On 22.05.2015 22:07, Konstantin Khorenko wrote:
> > On 05/20/2015 12:00 PM, Vladimir Davydov wrote:
> >> It is called by the showmem sysctl. Hell knows why it was added and who
> >> would ever used it.
> > It's not about sysctl, but about sysrq and we used it heavily until we start getting crash dumps from most of nodes.
> > => you forgot to get rid of other parts of that as well:
> > 
> > static struct sysrq_key_op sysrq_unrt_op = {
> >         .handler        = sysrq_handle_unrt,
> >         .help_msg       = "nice-all-RT-tasks(n)",
> >         .action_msg     = "Nice All RT Tasks",
> >         .enable_mask    = SYSRQ_ENABLE_RTNICE,
> > };
> > ...
> > static struct sysrq_key_op *sysrq_key_table[36] = {
> > ...
> >         &sysrq_showmem_op,              /* m */
> > 
> > Volodya, please, make the patch complete.
> > 
> > Vasya, do we still consider Alt+SysRQ+m useful?
> > i tend to agree to drop it for now.
> 
> I did not get, do you want to drop sysrq key for meminfo at all?

no

> Do you want to re-use 'm' key in sysrq?

no

Konstantin misunderstood the patch.

In RH6 we extended the info shown by this sysrq to dump per-UB info. It
is not clear why it was done - the commit message lacks any details, see
diff-ubc-sysrq-m-show-ubc-mem-state. Personally, I never used it and I
never saw anyone use it and I think it only clutters sysrq-M output and
increase our patch. So I return to the mainstream behavior.

Hope this explains everything.