Change memory calculation to choose a generous amount of memory.

[libguestfs.git] / src / guestfs.c

diff --git a/src/guestfs.c b/src/guestfs.c
index c1fb01d..15111db 100644 (file)
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -602,7 +602,7 @@ guestfs_config (guestfs_h *g,
 int
 guestfs_add_drive (guestfs_h *g, const char *filename)
 {
-  int len = strlen (filename) + 64;
+  size_t len = strlen (filename) + 64;
   char buf[len];
 
   if (strchr (filename, ',') != NULL) {
@@ -640,7 +640,8 @@ int
 guestfs_launch (guestfs_h *g)
 {
   static const char *dir_template = "/tmp/libguestfsXXXXXX";
-  int r, i, len, pmore, memsize;
+  int r, i, pmore, memsize;
+  size_t len;
   int wfd[2], rfd[2];
   int tries;
   const char *kernel_name = "vmlinuz." REPO "." host_cpu;
@@ -649,7 +650,6 @@ guestfs_launch (guestfs_h *g)
   char *kernel = NULL, *initrd = NULL;
   char unixsock[256];
   struct sockaddr_un addr;
-  struct stat statbuf;
 
   /* Configured? */
   if (!g->cmdline) {
@@ -709,39 +709,14 @@ guestfs_launch (guestfs_h *g)
     goto cleanup0;
   }
 
-  /* Choose a suitable memory size (in MB).  This is more art
-   * than science, but you can help by doing
-   *   ./configure --enable-debug-command
-   * and then running:
-   *   debug sh free
-   *   debug mem ''
-   * and seeing how much free memory is left for particular
-   * configurations.
-   *
-   * It's also helpful to report both the compressed and uncompressed
-   * size of the initramfs (ls -lh initramfs*.img; du -sh initramfs).
-   *
-   * XXX KVM virtio balloon driver?
+  /* Choose a suitable memory size.  Previously we tried to choose
+   * a minimal memory size, but this isn't really necessary since
+   * recent QEMU and KVM don't do anything nasty like locking
+   * memory into core any more.  This we can safely choose a
+   * large, generous amount of memory, and it'll just get swapped
+   * on smaller systems.
    */
-  if (stat (initrd, &statbuf) != -1) {
-    /* Approximate size of the initramfs after it is decompressed
-     * in kernel memory.  The compression factor is ~2.5-3.
-     */
-    memsize = 3 * statbuf.st_size / 1024 / 1024;
-
-    /* Approximate size used by the kernel. */
-    memsize += 10;
-
-    /* Want to give userspace some room, so: */
-    memsize += 128;
-
-#if SIZEOF_LONG == 8
-    /* On 64 bit, assume some overhead. */
-    memsize += 64;
-#endif
-  } else
-    memsize = 512;
-  
+  memsize = 384;
 
   /* Make the temporary directory containing the socket. */
   if (!g->tmpdir) {
@@ -787,7 +762,7 @@ guestfs_launch (guestfs_h *g)
 
     /* Linux kernel command line. */
     snprintf (append, sizeof append,
-             "console=ttyS0 guestfs=%s:%d%s",
+             "panic=1 console=ttyS0 guestfs=%s:%d%s",
              VMCHANNEL_ADDR, VMCHANNEL_PORT,
              g->verbose ? " guestfs_verbose=1" : "");
 
@@ -798,6 +773,7 @@ guestfs_launch (guestfs_h *g)
 #if 0
     add_cmdline (g, "-no-kqemu"); /* Avoids a warning. */
 #endif
+    add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
     add_cmdline (g, "-kernel");
     add_cmdline (g, (char *) kernel);
     add_cmdline (g, "-initrd");
@@ -1226,7 +1202,7 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
                 int watch, int fd, int events)
 {
   XDR xdr;
-  unsigned len;
+  u_int32_t len;
   int n;
 
   if (g->verbose)
@@ -1546,7 +1522,7 @@ guestfs__send_sync (guestfs_h *g, int proc_nr,
 {
   struct guestfs_message_header hdr;
   XDR xdr;
-  unsigned len;
+  u_int32_t len;
   int serial = g->msg_next_serial++;
   int sent;
   guestfs_main_loop *ml = guestfs_get_main_loop (g);
@@ -1725,7 +1701,7 @@ static int check_for_daemon_cancellation (guestfs_h *g);
 static int
 send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t buflen)
 {
-  unsigned len;
+  u_int32_t len;
   int sent;
   guestfs_chunk chunk;
   XDR xdr;
@@ -1850,13 +1826,14 @@ check_for_daemon_cancellation (guestfs_h *g)
 /* Synchronously receive a file. */
 
 /* Returns -1 = error, 0 = EOF, 1 = more data */
-static int receive_file_data_sync (guestfs_h *g, void **buf, int *len);
+static int receive_file_data_sync (guestfs_h *g, void **buf, size_t *len);
 
 int
 guestfs__receive_file_sync (guestfs_h *g, const char *filename)
 {
   void *buf;
-  int fd, r, len;
+  int fd, r;
+  size_t len;
 
   fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666);
   if (fd == -1) {
@@ -1964,11 +1941,12 @@ receive_file_cb (guestfs_h *g, void *data, XDR *xdr)
 /* Receive a chunk of file data. */
 /* Returns -1 = error, 0 = EOF, 1 = more data */
 static int
-receive_file_data_sync (guestfs_h *g, void **buf, int *len_r)
+receive_file_data_sync (guestfs_h *g, void **buf, size_t *len_r)
 {
   struct receive_file_ctx ctx;
   guestfs_main_loop *ml = guestfs_get_main_loop (g);
-  int i, len;
+  int i;
+  size_t len;
 
   ctx.count = 0;
   ctx.chunks = NULL;