1 files changed, 14 insertions, 8 deletions

diff --git a/src/unix/linux.c b/src/unix/linux.c
index ad881867..ad07430e 100644
--- a/src/unix/linux.c
+++ b/src/unix/linux.c
@@ -1385,6 +1385,12 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
 
     w->events = w->pevents;
     e.events = w->pevents;
+    if (w == &loop->async_io_watcher)
+      /* Enable edge-triggered mode on async_io_watcher(eventfd),
+       * so that we're able to eliminate the overhead of reading
+       * the eventfd via system call on each event loop wakeup.
+       */
+      e.events |= EPOLLET;
     e.data.fd = w->fd;
     fd = w->fd;
 
@@ -1632,12 +1638,12 @@ int uv_resident_set_memory(size_t* rss) {
   long val;
   int rc;
   int i;
-  
+
   /* rss: 24th element */
   rc = uv__slurp("/proc/self/stat", buf, sizeof(buf));
   if (rc < 0)
     return rc;
-    
+
   /* find the last ')' */
   s = strrchr(buf, ')');
   if (s == NULL)
@@ -2256,7 +2262,7 @@ uint64_t uv_get_available_memory(void) {
 }
 
 
-static int uv__get_cgroupv2_constrained_cpu(const char* cgroup, 
+static int uv__get_cgroupv2_constrained_cpu(const char* cgroup,
                                             uv__cpu_constraint* constraint) {
   char path[256];
   char buf[1024];
@@ -2267,7 +2273,7 @@ static int uv__get_cgroupv2_constrained_cpu(const char* cgroup,
 
   if (strncmp(cgroup, "0::/", 4) != 0)
     return UV_EINVAL;
-   
+
   /* Trim ending \n by replacing it with a 0 */
   cgroup_trimmed = cgroup + sizeof("0::/") - 1;      /* Skip the prefix "0::/" */
   cgroup_size = (int)strcspn(cgroup_trimmed, "\n");  /* Find the first slash */
@@ -2319,7 +2325,7 @@ static char* uv__cgroup1_find_cpu_controller(const char* cgroup,
   return cgroup_cpu;
 }
 
-static int uv__get_cgroupv1_constrained_cpu(const char* cgroup, 
+static int uv__get_cgroupv1_constrained_cpu(const char* cgroup,
                                             uv__cpu_constraint* constraint) {
   char path[256];
   char buf[1024];
@@ -2337,8 +2343,8 @@ static int uv__get_cgroupv1_constrained_cpu(const char* cgroup,
            cgroup_size, cgroup_cpu);
 
   if (uv__slurp(path, buf, sizeof(buf)) < 0)
-    return UV_EIO;  
-    
+    return UV_EIO;
+
   if (sscanf(buf, "%lld", &constraint->quota_per_period) != 1)
     return UV_EINVAL;
 
@@ -2360,7 +2366,7 @@ static int uv__get_cgroupv1_constrained_cpu(const char* cgroup,
   /* Read cpu.shares */
   if (uv__slurp(path, buf, sizeof(buf)) < 0)
     return UV_EIO;
-  
+
   if (sscanf(buf, "%u", &shares) != 1)
     return UV_EINVAL;