|From:||Con Kolivas <firstname.lastname@example.org>|
|Subject:||[ANNOUNCE] BFS CPU scheduler v0.323 for 2.6.35|
|Date:||Sat, 7 Aug 2010 10:07:09 +1000|
This is to announce the availability of the updated BFS CPU scheduler for linux kernel v2.6.35. http://ck.kolivas.org/patches/bfs/2.6.35-sched-bfs-323.patch General BFS documentation: http://ck.kolivas.org/patches/bfs/sched-BFS.txt This will be included in 2.6.35-ck1 which is to be announced shortly. If time permits and demand is present I will slowly port v323 to some of the earlier kernels again. Changes since the last announced version (0.318): The most significant change has been some architectural change to work with changes in the mainline kernel as of 2.6.35. As suspend / halt and cpu offline code has been changed, the whole offline cpu/online cpu code had to be modified in BFS to suit. Previously an affined task that was bound to an offlining CPU had a temporary affinity placed in an "unplugged" CPU mask. This system was fragile and placed an extra cpumask_t into task struct, and really only worked for offlining of all CPUs during suspend/halt when all came back online. Now, tasks that are affined to CPUs that are not currently online can temporarily run on any CPU. This makes the system more robust and should work properly on all types of suspend/halt. Thanks to Radoslaw and others in #ck for pointing out this issue and helping test the modified version. None of this should be visible in userland unless you were already having suspend issues. Alexei Podtelezhnikov pointed out that the code that modified the rr_interval was ugly and helped rework it to do close to what I desire in a much nicer fashion. Once again, the rr intervals have now been shrunk a little bit further, and do not go above 24ms on any sized machine by default. They can still be modified via /proc as per always. This may decrease throughput slightly but should keep latencies much more stable on the many-core machine. Also thanks to Alexei, a number of microoptimisations were done in the SCHED_ISO refractory testing code. Should not be user visible. Some debugging checks that weren't relevant to BFS were removed, and unnecessary preempt disable/enable calls were removed. May be user visible if you were getting warnings in dmesg previously. CPU load calculation for use by the cpu frequency subsystem was improved to properly tell how busy each individual cpu was. This may cause noticeable improvements in how quickly cpufreq adapts to load in the ondemand governor. The nohz_ratelimit function new in 2.6.35, and already noted to be buggy and slated for removal in 126.96.36.199 was added as a no op to prevent this bug from showing up on BFS, and to make easy patching come 188.8.131.52 Random other minor cleanups that I can't remember. Enjoy! -- -ck -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to email@example.com More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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