From 048c640a64fd064361382a8800de05c87ff630cb Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Mon, 10 Jun 2024 11:10:14 +0200 Subject: executor: optimize waiting for child processes exit Currently we sleep only for 1 ms, which may produce some excessive CPU load (we usually have 6/8 such processes waiting). Make it sleep for 10 ms, but also make the sleep return immediately on child exit. This shuold both improve latency and reduce CPU load. --- executor/executor_linux.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'executor/executor_linux.h') diff --git a/executor/executor_linux.h b/executor/executor_linux.h index 3956127cd..bfd81776f 100644 --- a/executor/executor_linux.h +++ b/executor/executor_linux.h @@ -67,6 +67,11 @@ static void os_init(int argc, char** argv, char* data, size_t data_size) got = mmap(data + data_size, SYZ_PAGE_SIZE, PROT_NONE, MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0); if (data + data_size != got) failmsg("mmap of right data PROT_NONE page failed", "want %p, got %p", data + data_size, got); + + // A SIGCHLD handler makes sleep in loop exit immediately return with EINTR with a child exits. + struct sigaction act = {}; + act.sa_handler = [](int) {}; + sigaction(SIGCHLD, &act, nullptr); } static intptr_t execute_syscall(const call_t* c, intptr_t a[kMaxArgs]) -- cgit mrf-deployment