Messages in this thread | | | Date | Wed, 30 Nov 2016 13:50:18 -0500 | From | Prarit Bhargava <> | Subject | Re: Odd build breakage in 4.9-rc7 |
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On 11/30/2016 01:36 PM, Linus Torvalds wrote: > On Wed, Nov 30, 2016 at 10:28 AM, Prarit Bhargava <prarit@redhat.com> wrote: > ]> >> In my case I tracked this to commit 3637efb00864 ("x86/mce: Add PCI quirks to >> identify Xeons with machine check recovery") which adds the include for >> generated/autoksyms.h. > > Ok, that at least makes some sense. The other blamed commit did not > seem to possibly make a difference. > >> Searching LKML and I came across a report from Ken Moffat from a month ago: >> >> http://marc.info/?l=linux-kernel&m=147794681124332&w=2 > > Does a "make clean" get rid of it forever? Or does it come back?
It comes back. The steps to reproduce this are:
1. checkout latest linux.git 2. make -j112
(IOW, it occurs 100% of the time for me on a clean tree.)
To work around the bug I have to do
1. checkout latest linux.git 2. comment out the include for generated/autoksyms.h at include/linux/export.h:81 3. compile with -j112
This fails loudly, but then I do
4. uncomment the include for generated/autoksyms.h at include/linux/export.h:81 5. make -j112
and this completes with a bootable kernel AFAICT.
> > If it's a one-time dependency issue that is because some header > dependency addition that the automatic dependency generator hadn't > caught, that might explain a bisection failure too: once the file > happens to get rebuilt (and the dependencies re-done), it starts > working even though the "happens to be rebuilt" had nothing to do with > the original bug.
Hopefully the linux-kbuild folks might be able to point us in the right direction for a fix.
P.
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