On Thu, Mar 29, 2018 at 04:53:43PM +0200, Martin Schwidefsky wrote: > On Thu, 29 Mar 2018 16:07:49 +0200 > Frederic Weisbecker <[email protected]> wrote: > > > On Thu, Mar 29, 2018 at 04:01:11PM +0200, Peter Zijlstra wrote: > > > On Thu, Mar 29, 2018 at 03:47:46PM +0200, Frederic Weisbecker wrote: > > > > On Thu, Mar 29, 2018 at 09:16:19AM +0200, Peter Zijlstra wrote: > > > > > On Thu, Mar 29, 2018 at 04:27:05AM +0200, Frederic Weisbecker wrote: > > > > > > The last user of __ARCH_SET_SOFTIRQ_PENDING has been converted to > > > > > > generic > > > > > > per-cpu softirq mask. We can now remove this conditional. > > > > > > > > > > This seems like half a cleanup; who still has local_softirq_pending() > > > > > after this? > > > > > > > > Only s390 because it uses lowcore to store such cpu data. > > > > > > Is it worth keeping it there? It seems an aweful shame to keep this > > > stuff special cased for just the one arch. At the very least this > > > should've mentioned s390 is special and why. > > > > Right, I thought well about moving that special case to s390. I can > > do that in v2. > > The lowcore optimization for softirq_pending field is not really needed, > just nice to have. But if there is a strong reason to make a common > definition for it we can certainly do that.
I think there is no need to. Lowcore is faster to access than per-cpu on s390 and we are dealing with a frequently accessed field. Plus lowcore is expected to be often cache-hot. But Peter is right that I should move the default implementation of or_softirq_pending() and set_softirq_pending() to s390 as it's the last user of these after this patchset. Thanks.
