Hello Torvald, On 01/24/2015 02:12 PM, Torvald Riegel wrote: > On Sat, 2015-01-24 at 12:35 +0100, Thomas Gleixner wrote: >> So we should never see -EINTR in the case of a spurious wakeup here. >> >> But, here is the not so good news: >> >> I did some archaeology. The restart handling of futex_wait() got >> introduced in kernel 2.6.22, so anything older than that will have >> the spurious -EINTR issues. >> >> futex_wait_pi() always had the restart handling and glibc folks back >> then (2006) requested that it should never return -EINTR, so it >> unconditionally restarts the syscall whether a signal had been >> delivered or not. >> >> So kernels >= 2.6.22 should never return -EINTR spuriously. If that >> happens it's a bug and needs to be fixed. > > Thanks for looking into this. > > Michael, can you include the above in the documentation please? This is > useful for userspace code like glibc that expects a minimum kernel > version. Thanks!
I've added some text to my draft to cover this point. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- 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/
