[rrd-developers] 'checking if msync with MS_ASYNC updates the files mtime' test depend on the running kernel

[Gilles Espinasse]

When compiling rrd-1.3.6 in a chroot, kernel compiled may not be the kernel
that will be used with rrdtool later.

I find that compiling from debian etch (2.6.18) or lenny (2.6.26) produce
different librrd* files as when compiling against a >=2.6.27 kernel.

As a workaround when you know what you do, it is possible to preset that
test so rrdlib will not depend on the kernel you run during compilation.

Add before the configure inside rrd directory
echo "rd_cv_ms_async=ok" > config.cache

and add to configure --cache-file=config.cache

Now, on any kernel you run, result will be
checking if msync with MS_ASYNC updates the files mtime... (cached) yes


Gilles