On Sat, Sep 13, 2014 at 1:21 AM, Kim Phillips <kim.phillips@xxxxxxxxxxxxx> wrote: > [adding Sandeep, Horia and netdev] > > On Fri, 12 Sep 2014 09:39:12 +0200 > Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx> wrote: > >> On Fri, Sep 12, 2014 at 2:49 AM, Kim Phillips >> <kim.phillips@xxxxxxxxxxxxx> wrote: >> > On Wed, 10 Sep 2014 10:34:47 +0200 >> > Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx> wrote: >> > >> >> The talitos driver can cause starvation of other softirqs and as such >> >> it can also cause rcu stalls like: >> > ... >> >> Work around this by processing a maximum amount of 16 finished requests >> >> and rescheduling the done-tasklet if any work is left. >> >> This allows other softirqs to run. >> > >> > 16 sounds rather arbitrary, and application-dependent - talitos' >> > FIFO size is 24. >> >> Yep, 16 is arbitrary, I can also do "fifo_len" if you prefer? >> >> > IIRC, netdev's NAPI can be refactored out of just being able to work >> > on network devices, and be made to apply to crypto devices, too. In >> > fact, some old Freescale hacks of this nature have improved >> > performance. Can we do something like refactor NAPI instead? >> >> That would indeed be nice but sounds like quite some more work and >> I won't have time to do so. Especially since my system was taken down >> completely by the talitos tasklet under some circumstances. If there is >> any work going on in that regard I'd be fine with just dropping that patch >> (and carrying it myself until the refactoring is done). > > I'm not aware of any, but to prove whether NAPI actually fixes the > issue, can you try applying this patch: > http://patchwork.ozlabs.org/patch/146094/ I guess this would fix it too. Will run some tests soon. Helmut -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
