On 3/26/2013 3:16 AM, Henrik Austad wrote: > ns2cycles use per_cpu variables, and will, eventually, find its way into > smp_processord_id(). This is not safe in a preemptible kernel, > preemption should ideally be disabled. > > BUG: using smp_processor_id() in preemptible [00000000] code: > systemd-modules/367 > caller is ns2cycles+0x40/0xb8 > > Starting stack dump of tid 367, pid 367 (systemd-modules) on cpu 2 at > cycle 20969956421 > frame 0: 0xfffffff70004b860 dump_stack+0x0/0x20 (sp 0xfffffe407993fa90) > frame 1: 0xfffffff7006abc28 debug_smp_processor_id+0x1a8/0x1e0 (sp > 0xfffffe407993fa90) > frame 2: 0xfffffff7004d7b40 ns2cycles+0x40/0xb8 (sp 0xfffffe407993fab8) > frame 3: 0xfffffff7004dc578 __ndelay+0x38/0x80 (sp 0xfffffe407993fae0) > > However, in this case: > > - the frequency is the same accross all cores > - we use the data read-only > - we do not scale the frequency > > Which means that we can use the __raw_get_cpu_var instead. > > Signed-off-by: Henrik Austad <[email protected]> > --- > arch/tile/kernel/time.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-)
Thanks - taken into the tile tree! -- Chris Metcalf, Tilera Corp. http://www.tilera.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
