On Sat, Apr 27 2013, Aaron Carroll wrote: > On 27 April 2013 03:43, Akers, Jason B <jason.b.akers@xxxxxxxxx> wrote: > > Fio hangs when run on the Android x86 emulator. > > > > Tracking through, I found that the last call made is shmget() (in init.c - setup_thread_area()). > > I believe that the hang is related to the fio syscall implementation for x86. > > > > os-android.h defines shmget as: syscall(__NR_shmget, __key, __size, __shmflg); > > > > In arch-x86.h __NR_shmget is defined to 29. This was added on April 11th (a415b2cc). > > > > Looking deeper, I see that syscall 29 is actually mapped to pause(). (see SYSCALLS.TXT in bionic/libc) I confirmed that sys_pause() was being called by using a kernel breakpoint. This explains why fio hangs. > > You are right, I added the 64bit syscall number. > > > Now the question is: What to do about it? > > * Either junk the __NR_shm* definitions, or move them to x86-64 for > future 64bit Android compatibility > * The shm* functions need different definitions for x86-32, because > there are no shm* syscalls. They appear to be multiplexed over an IPC > syscall. Hmm good point, I had (wrongly) assumed that the abi was in sync for 32 and 64-bit x86, but that is not the case. For x86, you have to do ipc(SHMGET, ...) etc to get at it. I'll move the definitions to x86-64 where they belong. > As Jens said this has nothing to do with Android per se, only that its > libc does not implement shm*() so we have to do it ourselves. Yep. Jason, it should be fairly easy to wire up ipc(). Or you can do the android variant, I'm fine with either. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
