File xenpaging.qemu.flush-cache.patch of Package xen.4218

Overview Repositories Revisions Requests Users Attributes Meta

File xenpaging.qemu.flush-cache.patch of Package xen.4218

Subject: xenpaging/qemu-dm: add command to flush buffer cache.

Add support for a xenstore dm command to flush qemu's buffer cache.

qemu will just keep mapping pages and not release them, which causes problems
for the memory pager (since the page is mapped, it won't get paged out). When
the pager has trouble finding a page to page out, it asks qemu to flush its
buffer, which releases all the page mappings. This makes it possible to find
pages to swap out agian.

Already-Signed-off-by: Patrick Colp <Patrick.Colp@citrix.com>
Signed-off-by: Olaf Hering <olaf@aepfle.de>

---
 tools/qemu-xen-traditional-dir-remote/xenstore.c |    3 +++
 1 file changed, 3 insertions(+)

Index: xen-4.5.0-testing/tools/qemu-xen-traditional-dir-remote/xenstore.c
===================================================================
--- xen-4.5.0-testing.orig/tools/qemu-xen-traditional-dir-remote/xenstore.c
+++ xen-4.5.0-testing/tools/qemu-xen-traditional-dir-remote/xenstore.c
@@ -1006,6 +1006,9 @@ static void xenstore_process_dm_command_
         do_pci_add(par);
         free(par);
 #endif
+    } else if (!strncmp(command, "flush-cache", len)) {
+        fprintf(logfile, "dm-command: flush caches\n");
+        qemu_invalidate_map_cache();
     } else {
         fprintf(logfile, "dm-command: unknown command\"%*s\"\n", len, command);
     }

Places

File xenpaging.qemu.flush-cache.patch of Package xen.4218

Places