Am 10.12.2014 um 12:59 schrieb Geert Uytterhoeven: > On Wed, Dec 10, 2014 at 11:49 AM, Richard Weinberger <rich...@nod.at> wrote: >> Am 10.12.2014 um 11:46 schrieb Miklos Szeredi: >>> The guilty commit is: >>> >>> 00f634bc522d "asm-generic: add generic futex for !CONFIG_SMP" >> >> Thanks a lot Miklos! >> Your bisecting faster than I do. >> >> Let's dig into the issue! > > Do you need "select HAVE_FUTEX_CMPXCHG if FUTEX"?
> Cfr. commit e571c58f313d35c5 ("m68k: Skip futex_atomic_cmpxchg_inatomic() > test") and commit 03b8c7b623c80af2 ("futex: Allow architectures to skip > futex_atomic_cmpxchg_inatomic() test"). Bingo! If UML selects HAVE_FUTEX_CMPXCHG the code path I've described in my previous mail is no longer taken and makes it work again. I did only a small test but nothing exploded so far. > BTW, I still think the real problem is the wrong address space, cfr. > "[PATCH/RFC] futex: Switch to USER_DS for futex test" > (http://www.spinics.net/lists/linux-m68k/msg06597.html), so you may also > want to try that. > However, that caused problems on s390, as it ran too early: > http://permalink.gmane.org/gmane.linux.kernel.next/30165 Yeah, this would also make sense for UML. Thanks, //richard ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel