On 05/04/2015 10:05 AM, Peter Zijlstra wrote:
On Thu, Apr 30, 2015 at 02:49:26PM -0400, Waiman Long wrote:
On 04/29/2015 02:11 PM, Peter Zijlstra wrote:
On Fri, Apr 24, 2015 at 02:56:42PM -0400, Waiman Long wrote:
In the pv_scan_next() function, the slow cmpxchg atomic operation is
performed e
On Thu, Apr 30, 2015 at 02:49:26PM -0400, Waiman Long wrote:
> On 04/29/2015 02:11 PM, Peter Zijlstra wrote:
> >On Fri, Apr 24, 2015 at 02:56:42PM -0400, Waiman Long wrote:
> >>In the pv_scan_next() function, the slow cmpxchg atomic operation is
> >>performed even if the other CPU is not even close
On 04/29/2015 02:27 PM, Linus Torvalds wrote:
On Wed, Apr 29, 2015 at 11:11 AM, Peter Zijlstra wrote:
On Fri, Apr 24, 2015 at 02:56:42PM -0400, Waiman Long wrote:
In the pv_scan_next() function, the slow cmpxchg atomic operation is
performed even if the other CPU is not even close to being hal
On 04/29/2015 02:11 PM, Peter Zijlstra wrote:
On Fri, Apr 24, 2015 at 02:56:42PM -0400, Waiman Long wrote:
In the pv_scan_next() function, the slow cmpxchg atomic operation is
performed even if the other CPU is not even close to being halted. This
extra cmpxchg can harm slowpath performance.
Th
On Wed, Apr 29, 2015 at 11:11 AM, Peter Zijlstra wrote:
> On Fri, Apr 24, 2015 at 02:56:42PM -0400, Waiman Long wrote:
>> In the pv_scan_next() function, the slow cmpxchg atomic operation is
>> performed even if the other CPU is not even close to being halted. This
>> extra cmpxchg can harm slowpa
On Fri, Apr 24, 2015 at 02:56:42PM -0400, Waiman Long wrote:
> In the pv_scan_next() function, the slow cmpxchg atomic operation is
> performed even if the other CPU is not even close to being halted. This
> extra cmpxchg can harm slowpath performance.
>
> This patch introduces the new mayhalt fla
In the pv_scan_next() function, the slow cmpxchg atomic operation is
performed even if the other CPU is not even close to being halted. This
extra cmpxchg can harm slowpath performance.
This patch introduces the new mayhalt flag to indicate if the other
spinning CPU is close to being halted or not
