On Fri, Apr 19, 2013 at 2:25 PM, Ingo Molnar <mi...@kernel.org> wrote: > > * Paul Gortmaker <paul.gortma...@windriver.com> wrote: > >> On 13-04-18 07:14 AM, Peter Zijlstra wrote: >> > On Mon, 2013-04-15 at 11:33 +0200, Ingo Molnar wrote: >> >> * Paul Gortmaker <paul.gortma...@windriver.com> wrote: >> >> >> >>> Recent activity has had a focus on moving functionally related blocks of >> >>> stuff >> >>> out of sched/core.c into stand-alone files. The code relating to load >> >>> average >> >>> calculations has grown significantly enough recently to warrant placing >> >>> it in a >> >>> separate file. >> >>> >> >>> Here we do that, and in doing so, we shed ~20k of code from sched/core.c >> >>> (~10%). >> >>> >> >>> A couple small static functions in the core sched.h header were also >> >>> localized >> >>> to their singular user in sched/fair.c at the same time, with the goal >> >>> to also >> >>> reduce the amount of "broadcast" content in that sched.h file. >> >> >> >> Nice! >> >> >> >> Peter, is this (and the naming of the new file) fine with you too? >> > >> > Yes and no.. that is I do like the change, but I don't like the >> > filename. We have _waaaay_ too many different things we call load_avg. >> > >> > That said, I'm having a somewhat hard time coming up with a coherent >> > alternative :/ >> >> Several of the relocated functions start their name with "calc_load..." >> Does "calc_load.c" sound any better? > > Peter has a point about load_avg being somewhat of a misnomer: that's not your > fault in any way, we created overlapping naming within the scheduler and are > now > hurting from it. > > Here are the main scheduler 'load' concepts we have right now: > > - The externally visible 'average load' value extracted by tools like 'top' > via > /proc/loadavg and handled by fs/proc/loadavg.c. Internally the naming is > all > over the map: the fields that are updated are named 'avenrun[]', most other > variables and methods are named calc_load_*(), and a few callbacks are > named > *_cpu_load_*(). > > - rq->cpu_load, a weighted, vectored scheduler-internal notion of task load > average with multiple run length averages. Only exposed by debug > interfaces but > otherwise relied on by the scheduler for SMP load balancing. > > - se->avg - per entity (per task) load average. This is integrated > differently > from the cpu_load - but work is ongoing to possibly integrate it with the > rq->cpu_load metric. This metric is used for CPU internal execution time > allocation and timeslicing, based on nice value priorities and cgroup > weights and constraints. > > Work is ongoing to integrate rq->cpu_load and se->avg - eventually they will > become one metric. > > It might eventually make sense to integrate the 'average load' calculation as > well > with all this - as they really have a similar purpose, the avenload[] vector > of > averages is conceptually similar to the rq->cpu_load[] vector of averages. > > So I'd suggest to side-step all that existing confusion and simply name the > new > file kernel/sched/proc.c - our external /proc scheduler ABI towards userspace. > This is similar to the already existing kernel/irq/proc.c pattern. > Well, kernel/sched/stat.c - also exposes scheduler ABI to userspace. Aren't these things going to introduce confusion (stat.c and proc.c under same sched directory) ?
Thanks, Rakib -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
