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| author |   Roger Pau Monne <roger.pau@citrix.com> | 2013-04-17 20:18:56 +0200 |
|---|---|---|
| committer |   Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-04-18 09:29:22 -0400 |
| commit | c6cc142dac52e62e1e8a2aff5de1300202b96c66 (patch) | |
| tree | 6123fb46fd4f4e3c8460852c9b215edc7a1f1c7a /drivers/block/xen-blkback/common.h | |
| parent | xen-blkback: print stats about persistent grants (diff) | |
| download | linux-dev-c6cc142dac52e62e1e8a2aff5de1300202b96c66.tar.xz linux-dev-c6cc142dac52e62e1e8a2aff5de1300202b96c66.zip | |
xen-blkback: use balloon pages for all mappings
Using balloon pages for all granted pages allows us to simplify the
logic in blkback, especially in the xen_blkbk_map function, since now
we can decide if we want to map a grant persistently or not after we
have actually mapped it. This could not be done before because
persistent grants used ballooned pages, whereas non-persistent grants
used pages from the kernel.
This patch also introduces several changes, the first one is that the
list of free pages is no longer global, now each blkback instance has
it's own list of free pages that can be used to map grants. Also, a
run time parameter (max_buffer_pages) has been added in order to tune
the maximum number of free pages each blkback instance will keep in
it's buffer.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.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 | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 60103e2517ba..6c73c3855e65 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -220,6 +220,11 @@ struct xen_blkif { struct rb_root persistent_gnts; unsigned int persistent_gnt_c; + /* buffer of free pages to map grant refs */ + spinlock_t free_pages_lock; + int free_pages_num; + struct list_head free_pages; + /* statistics */ unsigned long st_print; unsigned long long st_rd_req; |