sstate.bbclass: get the number of threads from BB_NUMBER_THREADS

- bitbake BB_NUMBER_THREADS uses cpu_count from oe utils that uses
the python os.sched_getaffinity and it is more acurrate.

 grep -nH ^BB_NUMBER_THREADS meta/conf/bitbake.conf
 meta/conf/bitbake.conf:806:BB_NUMBER_THREADS ?= "${@oe.utils.cpu_count()}"

- multiprocessing.cpu_count() returns the number of CPUs on the host,
not the number of usable CPUs on the host. If the user is using
scheduler affinity then the number of usable CPUs may be less,
so when determining how many cores we can use check the affinity instead.

Signed-off-by: Jose Quaresma <quaresma.jose@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/classes/sstate.bbclass b/meta/classes/sstate.bbclass
index 2175ace4c40114c49a9373e3dfb7636a819343b3..d7f1b3f26ed9006e9a864126468888ff308d53a9 100644 (file)
--- a/meta/classes/sstate.bbclass
+++ b/meta/classes/sstate.bbclass
@@ -971,13 +971,12 @@ def sstate_checkhashes(sq_data, d, siginfo=False, currentcount=0, summary=True,
             tasklist.append((tid, sstatefile))
 
         if tasklist:
+            nproc = min(int(d.getVar("BB_NUMBER_THREADS")), len(tasklist))
+
             if len(tasklist) >= min_tasks:
                 msg = "Checking sstate mirror object availability"
                 bb.event.fire(bb.event.ProcessStarted(msg, len(tasklist)), d)
 
-            import multiprocessing
-            nproc = min(multiprocessing.cpu_count(), len(tasklist))
-
             bb.event.enable_threadlock()
             pool = oe.utils.ThreadedPool(nproc, len(tasklist),
                     worker_init=checkstatus_init, worker_end=checkstatus_end)