[PATCH] Don't allow mlock of more than real_mem-128MiB

[fio.git] / fio.c

diff --git a/fio.c b/fio.c
index 09f40afe4d8cbfac612aeb79a03f037a55a4e40a..e48a060e9bd2dc1a201742bbdf41b98efc518f25 100644 (file)
--- a/fio.c
+++ b/fio.c
@@ -2231,28 +2231,62 @@ static void reap_threads(int *nr_running, int *t_rate, int *m_rate)
        }
 }
 
+static void fio_unpin_memory(void *pinned)
+{
+       if (pinned) {
+               if (munlock(pinned, mlock_size) < 0)
+                       perror("munlock");
+               munmap(pinned, mlock_size);
+       }
+}
+
+static void *fio_pin_memory(void)
+{
+       long pagesize, pages;
+       void *ptr;
+
+       if (!mlock_size)
+               return NULL;
+
+       /*
+        * Don't allow mlock of more than real_mem-128MB
+        */
+       pagesize = sysconf(_SC_PAGESIZE);
+       pages = sysconf(_SC_PHYS_PAGES);
+       if (pages != -1 && pagesize != -1) {
+               unsigned long long real_mem = pages * pagesize;
+
+               if ((mlock_size + 128 * 1024 * 1024) > real_mem) {
+                       mlock_size = real_mem - 128 * 1024 * 1024;
+                       printf("fio: limiting mlocked memory to %lluMiB\n",
+                                                       mlock_size >> 20);
+               }
+       }
+
+       ptr = mmap(NULL, mlock_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | OS_MAP_ANON, 0, 0);
+       if (!ptr) {
+               perror("malloc locked mem");
+               return NULL;
+       }
+       if (mlock(ptr, mlock_size) < 0) {
+               munmap(ptr, mlock_size);
+               perror("mlock");
+               return NULL;
+       }
+
+       return ptr;
+}
+
 static void run_threads(void)
 {
        struct thread_data *td;
        unsigned long spent;
        int i, todo, nr_running, m_rate, t_rate, nr_started;
-       void *mlocked_mem = NULL;
-
-       printf("Starting %d thread%s\n", thread_number, thread_number > 1 ? "s" : "");
+       void *mlocked_mem;
 
-       if (mlock_size) {
-               mlocked_mem = malloc(mlock_size);
-               if (!mlocked_mem) {
-                       perror("malloc locked mem");
-                       return;
-               }
-               if (mlock(mlocked_mem, mlock_size) < 0) {
-                       free(mlocked_mem);
-                       perror("mlock");
-                       return;
-               }
-       }
+       mlocked_mem = fio_pin_memory();
 
+       printf("Starting %d thread%s\n", thread_number, thread_number > 1 ? "s" : "");
        fflush(stdout);
 
        signal(SIGINT, sig_handler);
@@ -2364,12 +2398,7 @@ static void run_threads(void)
        }
 
        update_io_ticks();
-
-       if (mlocked_mem) {
-               if (munlock(mlocked_mem, mlock_size) < 0)
-                       perror("munlock");
-               free(mlocked_mem);
-       }
+       fio_unpin_memory(mlocked_mem);
 }
 
 static void show_group_stats(struct group_run_stats *rs, int id)