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authorRichard Purdie <richard.purdie@linuxfoundation.org>2015-10-24 11:19:06 +0100
committerRichard Purdie <richard.purdie@linuxfoundation.org>2015-10-29 07:35:52 +0000
commit290534d3ff53b3c0a50e480863474d1785088c5a (patch)
tree011b9a73cbcf7c40fa6807716377a6355d408337 /bitbake/lib/bb/utils.py
parent3ebf7617d6c869f798807792918e1030b3ab66de (diff)
downloadpoky-290534d3ff53b3c0a50e480863474d1785088c5a.tar.gz
bitbake: build/utils: Add BB_TASK_IONICE_LEVEL support
Similarly to BB_TASK_NICE_LEVEL, add BB_TASK_IONICE_LEVEL which allows the ioprio of tasks to be adjusted. This is in response to various qemu runtime timeouts which have been witnessed on the autobuilder, seemingly due to IO starvation (we already use NICE_LEVEL to adjust tasks). This has a fairly urgent need to deal with certain 'random' failures we're seeing on the autobuilders in testing. The format of the data in the variable is BB_TASK_IONICE_LEVEL = "<class>.<prio>". For <class>, 2 is best effort (the default), 1 is real time and 3 is idle. You'd need superuser privileges to use realtime. The <prio> value is a default of 4, and can be set between 0 and 7 with 7 being lowest priority and 0 the highest. The user can set this freely with normal privileges Note that in order for this to take effect, you need the cfq scheduler selected for the backing block device. We could use nice wrapper functions for ioprio from modules like psutil however that would complicate bitbake dependencies. This version has some magic numbers but works on the main 32 and 64 bit x86 build architectures and can easily be extended if ever needed. When we move to python 3.x, we can likely replace this with standard calls. (Bitbake rev: b9471ad147b102c45d65f5ffd9521864df7ff9c1) Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'bitbake/lib/bb/utils.py')
-rw-r--r--bitbake/lib/bb/utils.py24
1 files changed, 24 insertions, 0 deletions
diff --git a/bitbake/lib/bb/utils.py b/bitbake/lib/bb/utils.py
index 9b550ef3f1..7f82687ae4 100644
--- a/bitbake/lib/bb/utils.py
+++ b/bitbake/lib/bb/utils.py
@@ -1311,3 +1311,27 @@ def signal_on_parent_exit(signame):
1311 result = cdll['libc.so.6'].prctl(PR_SET_PDEATHSIG, signum) 1311 result = cdll['libc.so.6'].prctl(PR_SET_PDEATHSIG, signum)
1312 if result != 0: 1312 if result != 0:
1313 raise PrCtlError('prctl failed with error code %s' % result) 1313 raise PrCtlError('prctl failed with error code %s' % result)
1314
1315#
1316# Manually call the ioprio syscall. We could depend on other libs like psutil
1317# however this gets us enough of what we need to bitbake for now without the
1318# dependency
1319#
1320_unamearch = os.uname()[4]
1321IOPRIO_WHO_PROCESS = 1
1322IOPRIO_CLASS_SHIFT = 13
1323
1324def ioprio_set(who, cls, value):
1325 NR_ioprio_set = None
1326 if _unamearch == "x86_64":
1327 NR_ioprio_set = 251
1328 elif _unamearch[0] == "i" and _unamearch[2:3] == "86":
1329 NR_ioprio_set = 289
1330
1331 if NR_ioprio_set:
1332 ioprio = value | (cls << IOPRIO_CLASS_SHIFT)
1333 rc = cdll['libc.so.6'].syscall(NR_ioprio_set, IOPRIO_WHO_PROCESS, who, ioprio)
1334 if rc != 0:
1335 raise ValueError("Unable to set ioprio, syscall returned %s" % rc)
1336 else:
1337 bb.warn("Unable to set IO Prio for arch %s" % _unamearch)