| Message ID | alpine.LFD.2.20.1611301726240.1715@knanqh.ubzr |
|---|---|
| State | New |
| Headers | show |
On 11/30/2016 05:41 PM, Nicolas Pitre wrote: > On Wed, 30 Nov 2016, Linus Torvalds wrote: > >> On Wed, Nov 30, 2016 at 10:50 AM, Prarit Bhargava <prarit@redhat.com> wrote: >>> >>> 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.) > > I don't have access to such hardware where -j112 could ever make sense. :-) :) I could push the builds onto the -j256 but I'm doing other stuff over there. :) > In other words, I can't reproduce regardless of the -j value I try. > >> I suspect it's not new, it's just that you are able to hit the timing >> just right (and the new include presumable makes that just be much >> easier). > > Here's the best fix I can think of. I can't convince myself any other > location would be 100% safe. Obviously I can't confirm if this actually > fixes anything. > > ----- >8 > Subject: kbuild: make sure autoksyms.h exists early > I'm building with this patch on top of latest now. I will put it in a tight loop and clear the drop_caches between builds to see if I can make it fail. Thanks Nicolas -- your help is very much appreciated. P.
On 11/30/2016 05:41 PM, Nicolas Pitre wrote: > On Wed, 30 Nov 2016, Linus Torvalds wrote: > >> On Wed, Nov 30, 2016 at 10:50 AM, Prarit Bhargava <prarit@redhat.com> wrote: >>> >>> 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.) > > I don't have access to such hardware where -j112 could ever make sense. :-) > In other words, I can't reproduce regardless of the -j value I try. > >> I suspect it's not new, it's just that you are able to hit the timing >> just right (and the new include presumable makes that just be much >> easier). > > Here's the best fix I can think of. I can't convince myself any other > location would be 100% safe. Obviously I can't confirm if this actually > fixes anything. > > ----- >8 > Subject: kbuild: make sure autoksyms.h exists early > > Some people are able to trigger a race where autoksyms.h is used before > its empty version is even created. Let's create it at the same time as > the directory holding it is created. > > Signed-off-by: Nicolas Pitre <nico@linaro.org> > > diff --git a/Makefile b/Makefile > index 694111b43c..9f9c3b577c 100644 > --- a/Makefile > +++ b/Makefile > @@ -1019,8 +1019,6 @@ prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic > prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ > include/config/auto.conf > $(cmd_crmodverdir) > - $(Q)test -e include/generated/autoksyms.h || \ > - touch include/generated/autoksyms.h > > archprepare: archheaders archscripts prepare1 scripts_basic > > diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile > index ebced77deb..90a091b6ae 100644 > --- a/scripts/kconfig/Makefile > +++ b/scripts/kconfig/Makefile > @@ -35,6 +35,8 @@ nconfig: $(obj)/nconf > > silentoldconfig: $(obj)/conf > $(Q)mkdir -p include/config include/generated > + $(Q)test -e include/generated/autoksyms.h || \ > + touch include/generated/autoksyms.h > $< $(silent) --$@ $(Kconfig) > > localyesconfig localmodconfig: $(obj)/streamline_config.pl $(obj)/conf > The testing was successful. After testing an hour of builds with different -j values, I'm no longer seeing any compile issues when this patch is applied. When I remove the patch the compile error returns so I'm going to say that this patch fixed it. Thanks again Nicolas. Tested-by: Prarit Bhargava <prarit@redhat.com> P.
On 2016-12-01 9:03 AM, Prarit Bhargava wrote: > > > On 11/30/2016 05:41 PM, Nicolas Pitre wrote: >> On Wed, 30 Nov 2016, Linus Torvalds wrote: >> >>> On Wed, Nov 30, 2016 at 10:50 AM, Prarit Bhargava <prarit@redhat.com> wrote: >>>> >>>> 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.) >> >> I don't have access to such hardware where -j112 could ever make sense. :-) >> In other words, I can't reproduce regardless of the -j value I try. >> >>> I suspect it's not new, it's just that you are able to hit the timing >>> just right (and the new include presumable makes that just be much >>> easier). >> >> Here's the best fix I can think of. I can't convince myself any other >> location would be 100% safe. Obviously I can't confirm if this actually >> fixes anything. >> >> ----- >8 >> Subject: kbuild: make sure autoksyms.h exists early >> >> Some people are able to trigger a race where autoksyms.h is used before >> its empty version is even created. Let's create it at the same time as >> the directory holding it is created. >> >> Signed-off-by: Nicolas Pitre <nico@linaro.org> >> >> diff --git a/Makefile b/Makefile >> index 694111b43c..9f9c3b577c 100644 >> --- a/Makefile >> +++ b/Makefile >> @@ -1019,8 +1019,6 @@ prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic >> prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ >> include/config/auto.conf >> $(cmd_crmodverdir) >> - $(Q)test -e include/generated/autoksyms.h || \ >> - touch include/generated/autoksyms.h >> >> archprepare: archheaders archscripts prepare1 scripts_basic >> >> diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile >> index ebced77deb..90a091b6ae 100644 >> --- a/scripts/kconfig/Makefile >> +++ b/scripts/kconfig/Makefile >> @@ -35,6 +35,8 @@ nconfig: $(obj)/nconf >> >> silentoldconfig: $(obj)/conf >> $(Q)mkdir -p include/config include/generated >> + $(Q)test -e include/generated/autoksyms.h || \ >> + touch include/generated/autoksyms.h >> $< $(silent) --$@ $(Kconfig) >> >> localyesconfig localmodconfig: $(obj)/streamline_config.pl $(obj)/conf >> > > The testing was successful. > > After testing an hour of builds with different -j values, I'm no longer seeing > any compile issues when this patch is applied. When I remove the patch the > compile error returns so I'm going to say that this patch fixed it. > > Thanks again Nicolas. > > Tested-by: Prarit Bhargava <prarit@redhat.com> Looks good here as well, can do parallel make w/o reverting Tony's patches again. Tested-by: Jarod Wilson <jarod@redhat.com> -- Jarod Wilson jarod@redhat.com
diff --git a/Makefile b/Makefile index 694111b43c..9f9c3b577c 100644 --- a/Makefile +++ b/Makefile @@ -1019,8 +1019,6 @@ prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ include/config/auto.conf $(cmd_crmodverdir) - $(Q)test -e include/generated/autoksyms.h || \ - touch include/generated/autoksyms.h archprepare: archheaders archscripts prepare1 scripts_basic diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile index ebced77deb..90a091b6ae 100644 --- a/scripts/kconfig/Makefile +++ b/scripts/kconfig/Makefile @@ -35,6 +35,8 @@ nconfig: $(obj)/nconf silentoldconfig: $(obj)/conf $(Q)mkdir -p include/config include/generated + $(Q)test -e include/generated/autoksyms.h || \ + touch include/generated/autoksyms.h $< $(silent) --$@ $(Kconfig) localyesconfig localmodconfig: $(obj)/streamline_config.pl $(obj)/conf