From e438c57a640ac5afba366531be5e456b9fe22672 Mon Sep 17 00:00:00 2001 From: Martin Wilck Date: Sat, 7 Apr 2018 17:33:48 +0200 Subject: [PATCH] systemd-udevd: limit children-max by available memory (#8668) Udev workers consume typically 50-100MiB virtual memory. On systems with lots of CPUs and relatively low memory, that may easily cause workers to be OOM-killed. This patch limits the number of workers to 8 per GiB memory. But don't let the limit drop below the smallest value we had without this patch (8 + 1 * 2 = 10); on small systems, udev's memory footprint is likely lower. --- src/udev/udevd.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/udev/udevd.c b/src/udev/udevd.c index 254a725..006cdd3 100644 --- a/src/udev/udevd.c +++ b/src/udev/udevd.c @@ -1673,12 +1673,16 @@ int main(int argc, char *argv[]) { if (arg_children_max == 0) { cpu_set_t cpu_set; + unsigned long mem_limit; arg_children_max = 8; if (sched_getaffinity(0, sizeof(cpu_set), &cpu_set) == 0) arg_children_max += CPU_COUNT(&cpu_set) * 2; + mem_limit = physical_memory() / (128LU*1024*1024); + arg_children_max = MAX(10U, MIN(arg_children_max, mem_limit)); + log_debug("set children_max to %u", arg_children_max); } -- 2.7.4