[Xen-changelog] [xen-4.0-testing] tmem: skip special case in alloc_heap_pages() if tmem holds no pages

["Xen patchbot-4.0-testing" <patchbot-4.0-testing@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1277918375 -3600
# Node ID 927dea73c8b2fe5086ab08f9f0f3252af71c88d1
# Parent  7dcfdd45bc9e8ff769381cb3e066e0f5b7877093
tmem: skip special case in alloc_heap_pages() if tmem holds no pages
Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
xen-unstable changeset:   21658:c362e793f0a0
xen-unstable date:        Wed Jun 23 23:23:22 2010 +0100
---
 xen/common/page_alloc.c |    9 ++++++---
 xen/common/tmem.c       |    5 +++++
 xen/include/xen/tmem.h  |    1 +
 3 files changed, 12 insertions(+), 3 deletions(-)

diff -r 7dcfdd45bc9e -r 927dea73c8b2 xen/common/page_alloc.c
--- a/xen/common/page_alloc.c   Tue Jun 22 07:31:14 2010 +0100
+++ b/xen/common/page_alloc.c   Wed Jun 30 18:19:35 2010 +0100
@@ -316,11 +316,14 @@ static struct page_info *alloc_heap_page
     spin_lock(&heap_lock);
 
     /*
-     * TMEM: When available memory is scarce, allow only mid-size allocations
-     * to avoid worst of fragmentation issues. Others try TMEM pools then fail.
+     * TMEM: When available memory is scarce due to tmem absorbing it, allow
+     * only mid-size allocations to avoid worst of fragmentation issues.
+     * Others try tmem pools then fail.  This is a workaround until all
+     * post-dom0-creation-multi-page allocations can be eliminated.
      */
     if ( opt_tmem && ((order == 0) || (order >= 9)) &&
-         (total_avail_pages <= midsize_alloc_zone_pages) )
+         (total_avail_pages <= midsize_alloc_zone_pages) &&
+         tmem_freeable_pages() )
         goto try_tmem;
 
     /*
diff -r 7dcfdd45bc9e -r 927dea73c8b2 xen/common/tmem.c
--- a/xen/common/tmem.c Tue Jun 22 07:31:14 2010 +0100
+++ b/xen/common/tmem.c Wed Jun 30 18:19:35 2010 +0100
@@ -2850,6 +2850,11 @@ EXPORT void *tmem_relinquish_pages(unsig
     return pfp;
 }
 
+EXPORT unsigned long tmem_freeable_pages(void)
+{
+    return tmh_freeable_pages();
+}
+
 /* called at hypervisor startup */
 EXPORT void init_tmem(void)
 {
diff -r 7dcfdd45bc9e -r 927dea73c8b2 xen/include/xen/tmem.h
--- a/xen/include/xen/tmem.h    Tue Jun 22 07:31:14 2010 +0100
+++ b/xen/include/xen/tmem.h    Wed Jun 30 18:19:35 2010 +0100
@@ -12,6 +12,7 @@ extern void init_tmem(void);
 extern void init_tmem(void);
 extern void tmem_destroy(void *);
 extern void *tmem_relinquish_pages(unsigned int, unsigned int);
+extern unsigned long tmem_freeable_pages(void);
 extern int  opt_tmem;
 
 #endif /* __XEN_TMEM_H__ */

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