lkml.org 
[lkml]   [2011]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subjecttimerfd incompatibility on mips
Hi!

I've just found a problem with TFD_NONBLOCK flag that can be passed to
timerfd_create.

<uclibc>/libc/sysdeps/linux/common/sys/timerfd.h which is installed
to /usr/include/sys/timerfd.h defines TFD_NONBLOCK as 04000 ie 0x800.
BTW glibc/eglibc headers do the same thing.

<linux>/include/linux/timerfd.h declares it as O_NONBLOCK which is
defined in fcntl.h. Usually O_NONBLOCK is 0x800 too but some
architectures including MIPS it redefine it:

arch/mips/include/asm/fcntl.h:#define O_NONBLOCK 0x0080
arch/alpha/include/asm/fcntl.h:#define O_NONBLOCK 00004
arch/sparc/include/asm/fcntl.h:#define O_NONBLOCK 0x4000
arch/parisc/include/asm/fcntl.h:#define O_NONBLOCK 000200004

My tests show that kernel thinks that TFD_NONBLOCK is 0x80 on MIPS. I
get what I want when I pass 0x80 and EINVAL when I pass 0x800. I don't
know why there are such uncertain things in Linux. Probably the problem
should be fixed in the kernel.

Right now one cannot use timerfd_create(..., TFD_NONBLOCK) on MIPS but
can use timerfd_create(..., O_NONBLOCK) instead.

--
Alexander
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2011-01-28 01:27    [W:0.617 / U:0.692 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site