* [PATCH] build: Add BB_TASK_NICE_LEVEL to task code
@ 2013-09-20 10:29 Richard Purdie
2013-09-20 11:09 ` Paul Eggleton
0 siblings, 1 reply; 3+ messages in thread
From: Richard Purdie @ 2013-09-20 10:29 UTC (permalink / raw)
To: bitbake-devel
On Linux its not possible for processes to regain a previous nice level after
it has changed. Its therefore not possible to have a core low priority and
then raise the priorities of individual tasks.
This variable allows us to do something like:
BB_TASK_NICE_LEVEL = "5"
BB_TASK_NICE_LEVEL_task-testimage = "0"
to give priority to specific tasks which the BB_NICE_LEVEL functionality
doesn't give us the option of.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
---
diff --git a/bitbake/lib/bb/build.py b/bitbake/lib/bb/build.py
index 8aec699..9addd71 100644
--- a/bitbake/lib/bb/build.py
+++ b/bitbake/lib/bb/build.py
@@ -346,6 +346,13 @@ def _exec_task(fn, task, d, quieterr):
if not tempdir:
bb.fatal("T variable not set, unable to build")
+ # Change nice level if we're asked to
+ nice = localdata.getVar("BB_TASK_NICE_LEVEL", True)
+ if nice:
+ curnice = os.nice(0)
+ nice = int(nice) - curnice
+ logger.debug(1, "Renice to %s " % os.nice(nice))
+
bb.utils.mkdirhier(tempdir)
# Determine the logfile to generate
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] build: Add BB_TASK_NICE_LEVEL to task code
2013-09-20 10:29 [PATCH] build: Add BB_TASK_NICE_LEVEL to task code Richard Purdie
@ 2013-09-20 11:09 ` Paul Eggleton
2013-09-20 11:59 ` Richard Purdie
0 siblings, 1 reply; 3+ messages in thread
From: Paul Eggleton @ 2013-09-20 11:09 UTC (permalink / raw)
To: Richard Purdie; +Cc: bitbake-devel
On Friday 20 September 2013 11:29:47 Richard Purdie wrote:
> On Linux its not possible for processes to regain a previous nice level
> after it has changed. Its therefore not possible to have a core low
> priority and then raise the priorities of individual tasks.
>
> This variable allows us to do something like:
>
> BB_TASK_NICE_LEVEL = "5"
> BB_TASK_NICE_LEVEL_task-testimage = "0"
>
> to give priority to specific tasks which the BB_NICE_LEVEL functionality
> doesn't give us the option of.
>
> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
> ---
> diff --git a/bitbake/lib/bb/build.py b/bitbake/lib/bb/build.py
> index 8aec699..9addd71 100644
> --- a/bitbake/lib/bb/build.py
> +++ b/bitbake/lib/bb/build.py
> @@ -346,6 +346,13 @@ def _exec_task(fn, task, d, quieterr):
> if not tempdir:
> bb.fatal("T variable not set, unable to build")
>
> + # Change nice level if we're asked to
> + nice = localdata.getVar("BB_TASK_NICE_LEVEL", True)
> + if nice:
> + curnice = os.nice(0)
> + nice = int(nice) - curnice
> + logger.debug(1, "Renice to %s " % os.nice(nice))
It's a matter of style to be sure, but I think it's better not to have debug
statements that do more than just printing debug output - could the latter be
split onto two lines? Then it's easy to tell what's being done.
Cheers,
Paul
--
Paul Eggleton
Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] build: Add BB_TASK_NICE_LEVEL to task code
2013-09-20 11:09 ` Paul Eggleton
@ 2013-09-20 11:59 ` Richard Purdie
0 siblings, 0 replies; 3+ messages in thread
From: Richard Purdie @ 2013-09-20 11:59 UTC (permalink / raw)
To: Paul Eggleton; +Cc: bitbake-devel
On Fri, 2013-09-20 at 12:09 +0100, Paul Eggleton wrote:
> On Friday 20 September 2013 11:29:47 Richard Purdie wrote:
> > On Linux its not possible for processes to regain a previous nice level
> > after it has changed. Its therefore not possible to have a core low
> > priority and then raise the priorities of individual tasks.
> >
> > This variable allows us to do something like:
> >
> > BB_TASK_NICE_LEVEL = "5"
> > BB_TASK_NICE_LEVEL_task-testimage = "0"
> >
> > to give priority to specific tasks which the BB_NICE_LEVEL functionality
> > doesn't give us the option of.
> >
> > Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
> > ---
> > diff --git a/bitbake/lib/bb/build.py b/bitbake/lib/bb/build.py
> > index 8aec699..9addd71 100644
> > --- a/bitbake/lib/bb/build.py
> > +++ b/bitbake/lib/bb/build.py
> > @@ -346,6 +346,13 @@ def _exec_task(fn, task, d, quieterr):
> > if not tempdir:
> > bb.fatal("T variable not set, unable to build")
> >
> > + # Change nice level if we're asked to
> > + nice = localdata.getVar("BB_TASK_NICE_LEVEL", True)
> > + if nice:
> > + curnice = os.nice(0)
> > + nice = int(nice) - curnice
> > + logger.debug(1, "Renice to %s " % os.nice(nice))
>
> It's a matter of style to be sure, but I think it's better not to have debug
> statements that do more than just printing debug output - could the latter be
> split onto two lines? Then it's easy to tell what's being done.
Agreed, although this is a copy and paste of the BB_NICE_LEVEL code so
we should probably fix both.
Cheers,
Richard
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-09-20 10:29 [PATCH] build: Add BB_TASK_NICE_LEVEL to task code Richard Purdie
2013-09-20 11:09 ` Paul Eggleton
2013-09-20 11:59 ` Richard Purdie
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