On 03/07/2018 09:56, Chris Wilson wrote:
sysinfo() doesn't include all reclaimable memory. In particular it excludes the majority of global_node_page_state(NR_FILE_PAGES), reclaimable pages that are a copy of on-disk files It seems the only way to obtain this counter is by parsing /proc/meminfo. For comparison, check vm_enough_memory() which includes NR_FILE_PAGES as available (sadly there's no way to call vm_enough_memory() directly either!)v2: Pay attention to what one writes. v3: Trim off redundant space, and warn if the requested tags do not match the layout of /proc/meminfo. Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com> --- lib/intel_os.c | 44 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 5 deletions(-) diff --git a/lib/intel_os.c b/lib/intel_os.c index 885ffdcec..29a27272e 100644 --- a/lib/intel_os.c +++ b/lib/intel_os.c @@ -84,6 +84,19 @@ intel_get_total_ram_mb(void) return retval / (1024*1024); }+static uint64_t get_meminfo(const char *info, const char *tag)+{ + const char *str; + unsigned long val; + + str = strstr(info, tag); + if (str && sscanf(str + strlen(tag), " %lu", &val) == 1) + return (uint64_t)val << 10; + + igt_warn("Unrecognised /proc/meminfo field: '%s'\n", tag); + return 0; +} + /** * intel_get_avail_ram_mb: * @@ -96,17 +109,38 @@ intel_get_avail_ram_mb(void) uint64_t retval;#ifdef HAVE_STRUCT_SYSINFO_TOTALRAM /* Linux */- struct sysinfo sysinf; + char *info; int fd;fd = drm_open_driver(DRIVER_INTEL);intel_purge_vm_caches(fd); close(fd);- igt_assert(sysinfo(&sysinf) == 0);- retval = sysinf.freeram; - retval += min(sysinf.freeswap, sysinf.bufferram); - retval *= sysinf.mem_unit; + fd = open("/proc", O_RDONLY); + info = igt_sysfs_get(fd, "meminfo"); + close(fd); + + if (info) { + retval = get_meminfo(info, "MemAvailable:"); + retval += get_meminfo(info, "Buffers:"); + /* + * Include the file+swap cache as "available" for the test. + * We believe that we can revoke these pages back to their + * on disk counterpart, with no loss of functionality while + * the test runs using those pages for ourselves without the + * test itself being swapped to disk. + */ + retval += get_meminfo(info, "Cached:"); + retval += get_meminfo(info, "SwapCached:"); + free(info); + } else { + struct sysinfo sysinf; + + 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;
Reviewed-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com> Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
