lib: Extract mlock probing

We already have the routine we need in drv_suspend. Let's move it to lib
and use it in the mlocking tests. We can also make it a bit faster if we
tweak the initial step and initial amount.
(I think it's safe to assume that we should be able to lock 3/4
of RAM, this cuts the probe time on my 32G SKL - from ~530s to ~180s)

v2: Use available mem, amend step, also lock outside of fork,
    early exit if the assumption is wrong (Chris)
    Update the function name in doc (Ewelina)
v3: Total for pin, available for initial lock (Chris)

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ewelina Musial <ewelina.musial@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ewelina Musial <ewelina.musial@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index 0eb96e44..9a962881 100644
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -209,6 +209,7 @@ void intel_purge_vm_caches(int fd);
 uint64_t intel_get_avail_ram_mb(void);
 uint64_t intel_get_total_ram_mb(void);
 uint64_t intel_get_total_swap_mb(void);
+size_t intel_get_total_pinnable_mem(void);
 
 int __intel_check_memory(uint64_t count, uint64_t size, unsigned mode,
 			 uint64_t *out_required, uint64_t *out_total);