lib: Conservatively include residual buffers in the available ram estimate

Add any buffers reported by sysinfo to the estimate of available memory.
We do ask the kernel to purge it's caches before reporting sysinfo, but
a few remain that may be forced out by our test usage, so include them.
However, be conservative and only allow them to be swapped out.

References: https://bugs.freedesktop.org/show_bug.cgi?id=105967
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/intel_os.c b/lib/intel_os.c
index 88a61f37..885ffdce 100644
--- a/lib/intel_os.c
+++ b/lib/intel_os.c
@@ -105,6 +105,7 @@ intel_get_avail_ram_mb(void)
 
 	igt_assert(sysinfo(&sysinf) == 0);
 	retval = sysinf.freeram;
+	retval += min(sysinf.freeswap, sysinf.bufferram);
 	retval *= sysinf.mem_unit;
 #elif defined(_SC_PAGESIZE) && defined(_SC_AVPHYS_PAGES) /* Solaris */
 	long pagesize, npages;