Re: 5.0-rc kernel hangs on early boot

[Mel Gorman]

On Wed, Feb 13, 2019 at 02:51:15PM +0300, Yury Norov wrote:
> On Wed, Feb 13, 2019 at 11:14:09AM +0000, Mel Gorman wrote:
> > On Wed, Feb 13, 2019 at 11:25:40AM +0300, Yury Norov wrote:
> > > Hi Mel, all,
> > > 
> > > My kernel on qemu/arm64 setup hangs at early boot since v5.0-rc1.
> > > Backtrace is not too verbose:
> > > (gdb) i threads
> > >   Id   Target Id         Frame
> > > * 1    Thread 1 (CPU#0 [running]) 0xffff000010a49b74 in __delay (cycles=4096)
> > >     at arch/arm64/lib/delay.c:49
> > >   2    Thread 2 (CPU#1 [halted ]) 0x0000000000000000 in ?? ()
> > >   3    Thread 3 (CPU#2 [halted ]) 0x0000000000000000 in ?? ()
> > >   4    Thread 4 (CPU#3 [halted ]) 0x0000000000000000 in ?? ()
> > > (gdb) bt
> > > #0  0xffff000010a49b74 in __delay (cycles=4096) at arch/arm64/lib/delay.c:49
> > > Backtrace stopped: previous frame identical to this frame (corrupt stack?)
> > > 
> > > Reverting the patch
> > > 1c30844d2dfe272d58c ("mm: reclaim small amounts of memory when an external
> > > fragmentation event occurs") together with following patch
> > > 73444bc4d8f92e46a20 ("mm, page_alloc: do not wake kswapd with zone lock held")
> > > helps me to boot normally. 
> > > 
> > 
> > Well, that's a bad start to any day. Thanks for tracking it down. Does
> > the following patch help? I can't test it properly as I didn't recreate
> > your boot image or initrd but this appears to get past the initial boot
> > phase at least.
> 
> Hi Mel,
> 
> The patch works for me. The day gets better indeed. :-)
> 
> Tested-by: Yury Norov <yury.norov@xxxxxxxxx>
> 

Thanks! I've resent the patch to Andrew so hopefully it'll be picked up
before 5.0 is released.

-- 
Mel Gorman
SUSE Labs