[OE-core] Over-pruning the sstate cache
mac at mcrowe.com
Wed Apr 13 15:27:04 UTC 2016
On Wednesday 13 April 2016 at 11:11:11 -0300, Otavio Salvador wrote:
> On Wed, Apr 13, 2016 at 11:01 AM, Mike Crowe <mac at mcrowe.com> wrote:
> > On Wednesday 13 April 2016 at 10:47:13 -0300, Otavio Salvador wrote:
> >> Couldn't this to be done, similar to the fetchall task?
> > That's the sort of thing I was thinking of with my "all_populate_sysroot"
> > task in my original question.
> > But, I've a working script using Richard's method now. I'll share it once
> > I've tested it a bit more.
> Having it as a task allows it to avoid races and like, when running
> inside of the BitBake. It also can reuse the metadata database
> information and ought to be faster. Once you share the script I will
> see if I can rework it to a task and see how it looks.
I'm not really sure how much my (not very pretty) script will have in
common with a task-based solution.
I agree that integrating it into Bitbake would be better though. At the
moment generating the locked-sigs.inc file is by far the slowest part of
the operation though.
Since you've requested it, here's the not-really-tested-properly script.
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# Update atime on sstate-cache files for locked-sigs.inc file.
# Mike Crowe <mac at mcrowe.com>
# If nothing needs recompiling when building an image then bitbake
# won't access the sstate files that are required to populate the
# sysroot. This means that they might be expired as being unused. To
# avoid the problem this script processes the "locked-sigs.inc" file
# generated by running "bitbake XXX --dump-signatures=none".
# These variables may need tweaking when the build environment changes
native_lsb_string = "Debian-8"
target_vendor = ""
target_os = "oe-linux-gnueabi"
host_os = "linux"
sstate_version = "3"
native_arches = [ 'x86-64' ]
sstate_cache_dir = "sstate-cache/"
# The start of a variable declaration that tells us the arch
variable_re = re.compile('^SIGGEN_LOCKEDSIGS_t-([^ ]*) = \"\\\\$')
# A single hash for a task
sig_re = re.compile('^ *([^:]+):([^:]+):([^:]+) \\\\$')
# Ignore the trailing quote, the final line and blank lines
ignore_re = re.compile('^( *\")|(SIGGEN_LOCKEDSIGS_TYPES_)|$')
arch1 = "noarch"
arch2 = "noarch"
def TouchMatches(pattern, deadline):
matches = glob.glob(pattern)
for match in matches:
# It's likely that we won't need to touch the file so it's
# cheaper to do the stat to check first than to always open
# the file for reading. The inode might be in cache but the
# file contents not.
if os.stat(match).st_atime < deadline:
# We can't use os.utime for this since we may not own the
f = open(match, 'r')
# We actually have to read something from the file in
# order to update atime.
# In order to avoid unnecessarily thrashing the disk we only want to
# modify the atime of the file if the atime is more than a day ago.
# This matches the behaviour of the "relatime" mount option. We allow
# a bit of leeway in case we take a long time to run and the expiry
# script wants to expire stuff that's only more than a day old though.
deadline = time.time() - 23 * 3600
line_number = 0
for line in open("locked-sigs.inc", "r"):
line_number += 1
line = line.rstrip()
variable_match = variable_re.match(line)
arch = variable_match.group(1)
arch_underscore = arch.replace("-", "_")
if arch in native_arches:
dir = sstate_cache_dir + native_lsb_string + "/"
arch1 = arch_underscore + "-" + host_os
arch2 = arch_underscore
dir = sstate_cache_dir
arch1 = arch_underscore + target_vendor + "-" + target_os
arch2 = arch_underscore
sig_match = sig_re.match(line)
pn = sig_match.group(1)
task = sig_match.group(2)[3:]
sig = sig_match.group(3)
arch_file = dir + sig[0:2] + "/sstate:" + pn + ":" + arch1 + ":*:*:" + arch2 + ":" + sstate_version + ":" + sig + "_" + task + ".tgz"
noarch_file = dir + sig[0:2] + "/sstate:" + pn + "::*:*::" + sstate_version + ":" + sig + "_" + task + ".tgz"
sys.stderr.write('touch-sstate: Unparsed line %d\n' % line_number)
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