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From: "Ross Burton" <ross@burtonini.com>
To: openembedded-core@lists.openembedded.org
Subject: [PATCH 2/7] utils: respect scheduler affinity in cpu_count()
Date: Mon, 28 Sep 2020 17:18:55 +0100	[thread overview]
Message-ID: <20200928161900.452970-2-ross.burton@arm.com> (raw)
In-Reply-To: <20200928161900.452970-1-ross.burton@arm.com>

cpu_count() returns multiprocessing.cpu_count() but that is simply returns
os.cpu_count() so we could use that directly.

However this 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: Ross Burton <ross.burton@arm.com>
---
 meta/lib/oe/utils.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/meta/lib/oe/utils.py b/meta/lib/oe/utils.py
index 13f4271da0..468c76f30f 100644
--- a/meta/lib/oe/utils.py
+++ b/meta/lib/oe/utils.py
@@ -249,8 +249,7 @@ def trim_version(version, num_parts=2):
     return trimmed
 
 def cpu_count(at_least=1):
-    import multiprocessing
-    cpus = multiprocessing.cpu_count()
+    cpus = len(os.sched_getaffinity(0))
     return max(cpus, at_least)
 
 def execute_pre_post_process(d, cmds):
-- 
2.25.1


  reply	other threads:[~2020-09-28 16:19 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-28 16:18 [PATCH 1/7] glibc: make nscd optional Ross Burton
2020-09-28 16:18 ` Ross Burton [this message]
2020-09-28 16:18 ` [PATCH 3/7] rpm: disable libarchive use Ross Burton
2020-09-28 16:18 ` [PATCH 4/7] rpm: add PACKAGECONFIG for the systemd inhibit plugin Ross Burton
2020-09-28 16:18 ` [PATCH 5/7] utils: add umask changing context manager Ross Burton
2020-09-28 16:18 ` [PATCH 6/7] siggen: use correct umask when writing siginfo Ross Burton
2020-09-28 16:19 ` [PATCH 7/7] sstate: set mode explicitly when creating directories in sstate-cache Ross Burton
2020-09-28 16:40   ` [OE-core] " Mark Hatle
2020-09-28 16:55     ` Ross Burton
2020-09-28 23:44 ` [OE-core] [PATCH 1/7] glibc: make nscd optional Khem Raj

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