On Wed, Jan 07, 2015 at 09:00:34PM +0100, Christian Borntraeger wrote: > Am 07.01.2015 um 20:18 schrieb Guenter Roeck: > > On Wed, Jan 07, 2015 at 10:09:22AM -0800, Paul E. McKenney wrote: > >> On Wed, Jan 07, 2015 at 09:30:22AM -0800, Guenter Roeck wrote: > >>> On Wed, Jan 07, 2015 at 08:33:10AM -0800, Paul E. McKenney wrote: > >>>> On Wed, Jan 07, 2015 at 06:26:56AM -0800, Guenter Roeck wrote: > >>>>> On Wed, Jan 07, 2015 at 03:16:18PM +1100, Stephen Rothwell wrote: > >>>>>> Hi all, > >>>>>> > >>>>>> Changes since 20150106: > >>>>>> > >>>>>> *crickets* > >>>>>> > >>>>>> Non-merge commits (relative to Linus' tree): 1350 > >>>>>> 1543 files changed, 41856 insertions(+), 24250 deletions(-) > >>>>>> > >>>>>> ---------------------------------------------------------------------------- > >>>>>> > >>>>> > >>>>> New build failure for sh:dreamcast_defconfig: > >>>>> > >>>>> arch/sh/mm/gup.c: In function 'gup_get_pte': > >>>>> arch/sh/mm/gup.c:20:2: error: invalid initializer > >>>>> make[1]: *** [arch/sh/mm/gup.o] Error 1 > >>>>> > >>>>> bisect log: > >>>>> > >>>>> # bad: [7e3619a6de57f0257a2f6480182d2287ee05e314] Add linux-next specific files for 20150107 > >>>>> # good: [b1940cd21c0f4abdce101253e860feff547291b0] Linux 3.19-rc3 > >>>>> git bisect start 'HEAD' 'v3.19-rc3' > >>>>> # good: [c48667c5659248ff2b2fbff5cd23c43b5768e81b] Merge remote-tracking branch 'net-next/master' > >>>>> git bisect good c48667c5659248ff2b2fbff5cd23c43b5768e81b > >>>>> # good: [b8cf629ce7d554711dd7ab256b00e6110355e1d7] Merge remote-tracking branch 'mmc-uh/next' > >>>>> git bisect good b8cf629ce7d554711dd7ab256b00e6110355e1d7 > >>>>> # good: [cc52ff032bc2d91c78d7cf9aefcfa9e266ace816] Merge remote-tracking branch 'rcu/rcu/next' > >>>>> git bisect good cc52ff032bc2d91c78d7cf9aefcfa9e266ace816 > >>>>> # bad: [9634277bcdab7b9d6a91409dc11d85502aa2e74b] Merge remote-tracking branch 'access_once/linux-next' > >>>>> git bisect bad 9634277bcdab7b9d6a91409dc11d85502aa2e74b > >>>>> # good: [261379560ee6aa65b4869c94eda0d3d60773aca3] Merge remote-tracking branch 'scsi/for-next' > >>>>> git bisect good 261379560ee6aa65b4869c94eda0d3d60773aca3 > >>>>> # good: [38d45afa56bfca714780e45532760d64cd53b65b] Merge remote-tracking branch 'llvmlinux/for-next' > >>>>> git bisect good 38d45afa56bfca714780e45532760d64cd53b65b > >>>>> # good: [9afbe1ce2403c7d097bfaafcc5b27950040f7608] Merge remote-tracking branch 'y2038/y2038' > >>>>> git bisect good 9afbe1ce2403c7d097bfaafcc5b27950040f7608 > >>>>> # bad: [a91ed664749cbec0325ef9da7d12619d9bb72e2d] kernel: tighten rules for ACCESS ONCE > >>>>> git bisect bad a91ed664749cbec0325ef9da7d12619d9bb72e2d > >>>>> # good: [e3865cc4a17e979e6b2f26af026686fae5567096] x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE > >>>>> git bisect good e3865cc4a17e979e6b2f26af026686fae5567096 > >>>>> # good: [e2579c6f22ee0a43394d603cef6989dca98c5610] mm/gup: Replace ACCESS_ONCE with READ_ONCE > >>>>> git bisect good e2579c6f22ee0a43394d603cef6989dca98c5610 > >>>>> # first bad commit: [a91ed664749cbec0325ef9da7d12619d9bb72e2d] kernel: tighten rules for ACCESS ONCE > >>>>> > >>>>> Maybe the ACCESS_ONCE in the affected file should be replaced with READ_ONCE ? > >>>> > >>>> That is my belief. What happens when you try it? > >>>> > >>> Build passes, and my qemu tests pass as well. That doesn't mean > >>> that the change is correct, of course, since I don't know if the code > >>> in question is executed. > >> > >> Would it be possible to increment a counter at that location, then > >> print it out at some convenient point? > >> > > I made it simpler and just added a call to panic() ... which had no effect, > > so the function is not called in my qemu tests. Any idea what I would have > > to do to trigger a call ? > > > >>> Should I send a patch with the change ? > >> > >> I believe such a patch is needed. Testing would be good, but the patch > >> is what we were thinking of for this situation. > >> > > I'll probably send a patch marked "compile-tested only" if I can't find a way > > to test the change. > > I was going to fix as well, but I can certainly take your patch. Can you send it with proper signed-off-by etc and I will add it to the access_once tree? > Done. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
