In order to reduce the memory footprint we map into memory
the initrd using g_mapped_file_new() instead of reading it.
In this way we can share the initrd pages between multiple
instances of QEMU.
Suggested-by: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
---
hw/i386/pc.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 549c437050..b139589777 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1241,17 +1241,20 @@ static void load_linux(PCMachineState *pcms,
/* load initrd */
if (initrd_filename) {
+ GMappedFile *gmf;
gsize initrd_size;
gchar *initrd_data;
GError *gerr = NULL;
- if (!g_file_get_contents(initrd_filename, &initrd_data,
- &initrd_size, &gerr)) {
+ gmf = g_mapped_file_new(initrd_filename, false, &gerr);
+ if (!gmf) {
fprintf(stderr, "qemu: error reading initrd %s: %s\n",
initrd_filename, gerr->message);
exit(1);
}
+ initrd_data = g_mapped_file_get_contents(gmf);
+ initrd_size = g_mapped_file_get_length(gmf);
initrd_max = pcms->below_4g_mem_size - pcmc->acpi_data_size -
1;
if (initrd_size >= initrd_max) {
fprintf(stderr, "qemu: initrd is too large, cannot
support."
@@ -1378,6 +1381,7 @@ static void load_linux(PCMachineState *pcms,
/* load initrd */
if (initrd_filename) {
+ GMappedFile *gmf;
gsize initrd_size;
gchar *initrd_data;
GError *gerr = NULL;
@@ -1387,12 +1391,15 @@ static void load_linux(PCMachineState *pcms,
exit(1);
}
- if (!g_file_get_contents(initrd_filename, &initrd_data,
- &initrd_size, &gerr)) {
+ gmf = g_mapped_file_new(initrd_filename, false, &gerr);
+ if (!gmf) {
fprintf(stderr, "qemu: error reading initrd %s: %s\n",
initrd_filename, gerr->message);
exit(1);
}
+
+ initrd_data = g_mapped_file_get_contents(gmf);
+ initrd_size = g_mapped_file_get_length(gmf);
if (initrd_size >= initrd_max) {
fprintf(stderr, "qemu: initrd is too large, cannot support."
"(max: %"PRIu32", need %"PRId64")\n",
--
2.20.1
