Thread (25 messages) 25 messages, 6 authors, 2016-01-22

Re: [ANNOUNCE] 4.4-rc6-rt1

From: Tim Sander <hidden>
Date: 2016-01-07 12:15:39
Also in: lkml

Hi Sebastian

Thanks for your christmas present :-).

Am Mittwoch, 23. Dezember 2015, 23:57:55 schrieb Sebastian Andrzej Siewior:
Please don't continue reading before christmas eve (or morning,
depending on your schedule). If you don't celebrate christmas,
well go ahead.
Ok, i have to admit i am a little late to the party.
Dear RT folks!

I'm pleased to announce the v4.4-rc6-rt1 patch set. I tested it on my
AMD A10, 64bit. Nothing exploded so far, filesystem is still there.
I haven't tested it on anything else. Before someone asks: this does not
mean it does *not* work on ARM I simply did not try it.
With the trivial compile patch below it is working on ARM:
Specifically two Cortex A9 on a CycloneV from Altera.

The performance without load looks good:
# Total: 100000000 100000000
# Min Latencies: 00009 00009
# Avg Latencies: 00010 00010
# Max Latencies: 00022 00033

A short run with hackbench load reveals an latency "island" from 54-69µs on the first core.
There are no timer ticks with 34 to 53 µs delay.
# Total: 001000000 000999714
# Min Latencies: 00010 00009
# Avg Latencies: 00017 00010
# Max Latencies: 00069 00029

I will test further and report if i find strange occurences.
If you are brave then download it, install it and have fun. If something
breaks, please report it. If your machine starts blinking like a
christmas tree while using the patch then *please* send a photo.
Sorry no photos, no special blinking.
Best regards
Tim

Signed-off-by: Tim Sander <redacted>
--- linux-4.4-rc6/kernel/time/hrtimer.c.orig    2016-01-06 16:56:32.573527206 +0100                                                                                                                                                                                                                                                                                        
+++ linux-4.4-rc6/kernel/time/hrtimer.c 2016-01-06 16:56:48.213215320 +0100                                                                                                                                                                                                                                                                                                
@@ -1435,6 +1435,7 @@                                                                                                                                                                                                                                                                                                                                                      
                                                                                                                                                                                                                                                                                                                                                                           
 #endif                                                                                                                                                                                                                                                                                                                                                                    
                                                                                                                                                                                                                                                                                                                                                                           
+static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer);                                                                                                                                                                                                                                                                                                        
                                                                                                                                                                                                                                                                                                                                                                           
 static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now)                                                                                                                                                                                                                                                                                          
 {                                                                                                                                                                                                                                                                                                                                                                         
@@ -1490,8 +1491,6 @@                                                                                                                                                                                                                                                                                                                                                      
                raise_softirq_irqoff(HRTIMER_SOFTIRQ);                                                                                                                                                                                                                                                                                                                     
 }                                                                                                                                                                                                                                                                                                                                                                         
                                                                                                                                                                                                                                                                                                                                                                           
-static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer);                                                                                                                                                                                                                                                                                                        
-                                                                                                                                                                                                                                                                                                                                                                          
 #ifdef CONFIG_HIGH_RES_TIMERS                                                                                                                                                                                                                                                                                                                                             
                                                                                                                                                                                                                                                                                                                                                                           
 /*                                                                                                                                                                                                                                                                                                                                                                        
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help