Re: [PATCH] tell gcc optimizer to never introduce new data races
On Tue, Jun 10, 2014 at 04:53:27PM +0200, Peter Zijlstra wrote: > On Tue, Jun 10, 2014 at 03:23:36PM +0200, Jiri Kosina wrote: > > +# Tell gcc to never replace conditional load with a non-conditional one > > +KBUILD_CFLAGS += $(call cc-option,--param allow-store-data-races=0) > > + > > Why do we not want: -fmemory-model=safe? And should we not at the very > least also disable packed-store-data-races? Note that the option does not exist, even though it is mentioned in the documentation. Marek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] tell gcc optimizer to never introduce new data races
On Tue, Jun 10, 2014 at 04:53:27PM +0200, Peter Zijlstra wrote: On Tue, Jun 10, 2014 at 03:23:36PM +0200, Jiri Kosina wrote: +# Tell gcc to never replace conditional load with a non-conditional one +KBUILD_CFLAGS += $(call cc-option,--param allow-store-data-races=0) + Why do we not want: -fmemory-model=safe? And should we not at the very least also disable packed-store-data-races? Note that the option does not exist, even though it is mentioned in the documentation. Marek -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [RFC] gcc feature request: Moving blocks into sections
On Mon, Aug 05, 2013 at 11:34:55AM -0700, Linus Torvalds wrote: > On Mon, Aug 5, 2013 at 11:24 AM, Linus Torvalds > wrote: > > > > Ugh. I can see the attraction of your section thing for that case, I > > just get the feeling that we should be able to do better somehow. > > Hmm.. Quite frankly, Steven, for your use case I think you actually > want the C goto *labels* associated with a section. Which sounds like > it might be a cleaner syntax than making it about the basic block > anyway. FWIW, we also support hot/cold attributes for labels, thus e.g. if (bar ()) goto A; /* ... */ A: __attribute__((cold)) /* ... */ I don't know whether that might be useful for what you want or not though... Marek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [RFC] gcc feature request: Moving blocks into sections
On Mon, Aug 05, 2013 at 11:34:55AM -0700, Linus Torvalds wrote: On Mon, Aug 5, 2013 at 11:24 AM, Linus Torvalds torva...@linux-foundation.org wrote: Ugh. I can see the attraction of your section thing for that case, I just get the feeling that we should be able to do better somehow. Hmm.. Quite frankly, Steven, for your use case I think you actually want the C goto *labels* associated with a section. Which sounds like it might be a cleaner syntax than making it about the basic block anyway. FWIW, we also support hot/cold attributes for labels, thus e.g. if (bar ()) goto A; /* ... */ A: __attribute__((cold)) /* ... */ I don't know whether that might be useful for what you want or not though... Marek -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
