From: David van Moolenbroek <david@minix3.org>
Date: Sun, 6 Sep 2015 14:56:30 +0000 (+0200)
Subject: VM: allocate cache pages in mmap region
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zpipe.c?a=commitdiff_plain;h=refs%2Fchanges%2F54%2F3154%2F1;p=minix.git

VM: allocate cache pages in mmap region

That way, these pages are transferred during live update, as they
should.  This resolves a mfs crash after a number of live updates.

Change-Id: Ia53bec2692b2114c29b96a453beb0f915f56453a
---

diff --git a/minix/servers/vm/mem_cache.c b/minix/servers/vm/mem_cache.c
index 56c596dac..a702bb9fb 100644
--- a/minix/servers/vm/mem_cache.c
+++ b/minix/servers/vm/mem_cache.c
@@ -121,10 +121,13 @@ do_mapcache(message *msg)
 	 * in case instrumentation needs to allocate in-band metadata later.
 	 * This does effectively halve the usable part of the caller's address
 	 * space, though, so only do this if we are instrumenting at all.
+	 * Also make sure it falls within the mmap range, so that it is
+	 * transferred upon live update.  This again cuts the usable part of
+	 * the address space for caching purposes in half.
 	 */
 	alloc_bytes += VM_PAGE_SIZE;
 #endif
-	if (!(vr = map_page_region(caller, VM_PAGE_SIZE, VM_DATATOP,
+	if (!(vr = map_page_region(caller, VM_MMAPBASE, VM_MMAPTOP,
 	    alloc_bytes, VR_ANON | VR_WRITABLE, 0, &mem_type_cache))) {
 		printf("VM: map_page_region failed\n");
 		return ENOMEM;