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| author | Keir Fraser <keir.fraser@citrix.com> | 2009-12-09 10:44:56 +0000 |
|---|---|---|
| committer | Keir Fraser <keir.fraser@citrix.com> | 2009-12-09 10:44:56 +0000 |
| commit | 51010e4de3d40cd83549768c2cf10ecdcf6ee4a8 (patch) | |
| tree | ea18e6921dd14d075e32d4b263cb6a16d674203c /xen/include/xen/tmem_xen.h | |
| parent | 9905ac2b90a3e7cecd9e7dfe21c252362e7080b2 (diff) | |
| download | xen-51010e4de3d40cd83549768c2cf10ecdcf6ee4a8.tar.gz xen-51010e4de3d40cd83549768c2cf10ecdcf6ee4a8.tar.bz2 xen-51010e4de3d40cd83549768c2cf10ecdcf6ee4a8.zip | |
tmem: reclaim minimal memory proactively
When a single domain is using most/all of tmem memory
for ephemeral pages belonging to the same object, e.g.
when copying a single huge file larger than ephemeral
memory, long lists are traversed looking for a page to
evict that doesn't belong to this object (as pages in
the object for which a page is currently being inserted
are locked and cannot be evicted). This is essentially
a livelock.
Avoid this by proactively ensuring there is a margin
of available memory (1MB) before locks are taken on
the object.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Diffstat (limited to 'xen/include/xen/tmem_xen.h')
| -rw-r--r-- | xen/include/xen/tmem_xen.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/xen/include/xen/tmem_xen.h b/xen/include/xen/tmem_xen.h index 90b860a5f9..6095db8248 100644 --- a/xen/include/xen/tmem_xen.h +++ b/xen/include/xen/tmem_xen.h @@ -252,6 +252,11 @@ static inline unsigned long tmh_freeable_mb(void) (20 - PAGE_SHIFT); } +static inline unsigned long tmh_free_mb(void) +{ + return (tmh_avail_pages() + total_free_pages()) >> (20 - PAGE_SHIFT); +} + /* * Memory allocation for "infrastructure" data */ |