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| author | Juergen Gross <jgross@suse.com> | 2018-08-13 16:01:10 +0200 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2018-08-27 12:12:03 -0400 |
| commit | 973e5405f2f67ddbb2bf07b3ffc71908a37fea8e (patch) | |
| tree | 291850d68c314417cb2b074fddf9aa5171126a7a /drivers/block/xen-blkback/common.h | |
| parent | b86d865cb1cae1e61527ea0b8977078bbf694328 (diff) | |
| download | lwn-973e5405f2f67ddbb2bf07b3ffc71908a37fea8e.tar.gz lwn-973e5405f2f67ddbb2bf07b3ffc71908a37fea8e.zip | |
xen/blkback: don't keep persistent grants too long
Persistent grants are allocated until a threshold per ring is being
reached. Those grants won't be freed until the ring is being destroyed
meaning there will be resources kept busy which might no longer be
used.
Instead of freeing only persistent grants until the threshold is
reached add a timestamp and remove all persistent grants not having
been in use for a minute.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkback/common.h')
| -rw-r--r-- | drivers/block/xen-blkback/common.h | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index ecb35fe8ca8d..7bff72db3b7e 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -234,14 +234,9 @@ struct xen_vbd { struct backend_info; /* Number of available flags */ -#define PERSISTENT_GNT_FLAGS_SIZE 2 +#define PERSISTENT_GNT_FLAGS_SIZE 1 /* This persistent grant is currently in use */ #define PERSISTENT_GNT_ACTIVE 0 -/* - * This persistent grant has been used, this flag is set when we remove the - * PERSISTENT_GNT_ACTIVE, to know that this grant has been used recently. - */ -#define PERSISTENT_GNT_WAS_ACTIVE 1 /* Number of requests that we can fit in a ring */ #define XEN_BLKIF_REQS_PER_PAGE 32 @@ -250,6 +245,7 @@ struct persistent_gnt { struct page *page; grant_ref_t gnt; grant_handle_t handle; + unsigned long last_used; DECLARE_BITMAP(flags, PERSISTENT_GNT_FLAGS_SIZE); struct rb_node node; struct list_head remove_node; |