On Tue, Apr 28, 2015 at 08:53:18AM -0400, Rik van Riel wrote:
> So what can I do to move forward with this patch?
>
> It speeds up syscall entry / exit by 7% when nohz_full
> is enabled on a CPU...
>
> Should I have the irq block compiled in only when
> sizeof(cputime_t) > sizeof(long) ?
So I'm
On 04/27/2015 07:18 AM, Heiko Carstens wrote:
> On Sat, Apr 25, 2015 at 08:50:49AM -0400, Rik van Riel wrote:
>> On 04/25/2015 05:43 AM, Heiko Carstens wrote:
>>> ...the READ_ONCE() doesn't give you any guarantees about reading
>>> tsk->acct_timexpd in an atomic way.
>>> Well, actually you don't ne
On Sat, Apr 25, 2015 at 08:50:49AM -0400, Rik van Riel wrote:
> On 04/25/2015 05:43 AM, Heiko Carstens wrote:
> > ...the READ_ONCE() doesn't give you any guarantees about reading
> > tsk->acct_timexpd in an atomic way.
> > Well, actually you don't need atomic semantics, but only to make sure that
>
On 04/25/2015 05:43 AM, Heiko Carstens wrote:
> On Fri, Apr 24, 2015 at 11:16:53AM -0400, Rik van Riel wrote:
>> V2: introduce signed_cputime_t to deal with 64 bit cputime_t on
>> 32 bit architectures, and use READ_ONCE to ensure the value
>> is always read atomically (Heiko Karstens)
>
>
On Fri, Apr 24, 2015 at 11:16:53AM -0400, Rik van Riel wrote:
> V2: introduce signed_cputime_t to deal with 64 bit cputime_t on
> 32 bit architectures, and use READ_ONCE to ensure the value
> is always read atomically (Heiko Karstens)
Erm, that's not what I said ;)
READ_ONCE() only fixes t
The function __acct_update_integrals() is called both from irq context
and task context. This creates a race where irq context can advance
tsk->acct_timexpd to a value larger than time, leading to a negative
value, which causes a divide error. See commit 6d5b5acca9e5
("Fix fixpoint divide exception
6 matches
Mail list logo
