> 1. Blob after 325.xx.xx does not compile and does not work with our RT patches!
Sure it does.
make IGNORE_PREEMPT_RT_PRESENCE=1
SYSSRC=/usr/lib/modules/"${_kernver}/build" module
I've used every nvidia stable (or beta) driver post-325xx just fine on
-rt. The last remaning issues (for me) is getting nvidia to
remove/replace wbinvd(); and fix up scheduling bugs (with
semaphores)... or I will use mutexes, instead, i guess.
> 2. Nvidia developers specifically inserted function WBINVD to slowly work? :)
well, to find out this answer, i started a thread at nvidia's
developer forums and inquired about this. But i can tell you that the
Intel OSS driver was using wbinvdt() at some point in 3.10 cycle and
it was problematic there too, from what I understand.
> 3. SFENCE need on SMP systems. Although, delay in 1000 nanoseconds - it's awful
Would you care to goto into more detail on this? - I have seen no
negative impacts on my systems (I've been watching all system
resources and H/w related info, etc), but am curious about this, as
like i said, it is the source of problems in the nvidia blob and if
the Intel OSS driver was able to work around it, i don't see why
Nvidia couldn't do the same.
> 4. Do you really think, that mutex_lock/unlock more realtime than up/down?
Did i say that, Pavel ...What i can tell you is;
1. nvidia's driver on -rt when using semaphores, causing scheduling
bugs (ie: "scheduling while atomic"... that kind of thing),
periodically. It's non-fatal but happens 5-6 times a day on my
machines. I've yet to see even one scheduling while atomic bug, when
using mutexes. - so whether or not semaphores are more realtime, is
sort of a moot point for me - i use linux-rt for Proaudio - ie: GFX is
NOT as important, but what is important is that the (nvidia) driver
works properly (safely).
2. With Semaphores i seem to get more variance/jitter in my cyclictest
results or slightly higher latency spikes, then when i am using
mutexes. (and i feel a little safer without seeing a bunch of
scheduling while atomic bugs).
Jordan
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