diff --git a/lmkd.c b/lmkd.c index 3230310..838a5f4 100644 --- a/lmkd.c +++ b/lmkd.c @@ -1112,7 +1112,16 @@ int main(int argc __unused, char **argv __unused) { kill_timeout_ms = (unsigned long)property_get_int32("ro.lmk.kill_timeout_ms", 0); - if (mlockall(MCL_CURRENT | MCL_FUTURE)) + // MCL_ONFAULT pins pages as they fault instead of loading + // everything immediately all at once. (Which would be bad, + // because as of this writing, we have a lot of mapped pages we + // never use.) Old kernels will see MCL_ONFAULT and fail with + // EINVAL; we ignore this failure. + // + // N.B. read the man page for mlockall. MCL_CURRENT | MCL_ONFAULT + // pins ⊆ MCL_CURRENT, converging to just MCL_CURRENT as we fault + // in pages. + if (mlockall(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT) && errno != EINVAL) ALOGW("mlockall failed: errno=%d", errno); sched_setscheduler(0, SCHED_FIFO, ¶m);