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* [PATCH] xen/blkfront: remove unused macros
@ 2018-07-25  7:42 Juergen Gross
  2018-07-25  9:30 ` Roger Pau Monné
  2018-07-25 18:06 ` Jens Axboe
  0 siblings, 2 replies; 5+ messages in thread
From: Juergen Gross @ 2018-07-25  7:42 UTC (permalink / raw)
  To: linux-kernel, linux-block, xen-devel
  Cc: konrad.wilk, roger.pau, Juergen Gross

Remove some macros not used anywhere.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 drivers/block/xen-blkfront.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index b5cedccb5d7d..94300dbe358b 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -251,14 +251,9 @@ static DEFINE_SPINLOCK(minor_lock);
 #define GRANTS_PER_INDIRECT_FRAME \
 	(XEN_PAGE_SIZE / sizeof(struct blkif_request_segment))
 
-#define PSEGS_PER_INDIRECT_FRAME	\
-	(GRANTS_INDIRECT_FRAME / GRANTS_PSEGS)
-
 #define INDIRECT_GREFS(_grants)		\
 	DIV_ROUND_UP(_grants, GRANTS_PER_INDIRECT_FRAME)
 
-#define GREFS(_psegs)	((_psegs) * GRANTS_PER_PSEG)
-
 static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
 static void blkfront_gather_backend_features(struct blkfront_info *info);
 static int negotiate_mq(struct blkfront_info *info);
-- 
2.13.7


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* [PATCH 0/4] xen/blk: persistent grant rework
@ 2018-08-06 11:33 Juergen Gross
  2018-08-06 11:34 ` [PATCH] xen/blkfront: remove unused macros Juergen Gross
  0 siblings, 1 reply; 5+ messages in thread
From: Juergen Gross @ 2018-08-06 11:33 UTC (permalink / raw)
  To: linux-kernel, xen-devel, linux-block
  Cc: konrad.wilk, roger.pau, axboe, boris.ostrovsky, Juergen Gross

Persistent grants are used in the Xen's blkfront/blkback drivers to
avoid mapping/unmapping of I/O buffers in the backend for each I/O.

While this speeds up processing quite a bit there are problems related
to persistent grants in some configurations: domains with multiple
block devices making use of persistent grants might suffer from a lack
of grants if each of the block devices experienced a high I/O load at
some time. This is due to the number of persistent grants per device
only to be limited by a rather high maximum value, but never being
released even in case of longer times without any I/O.

This series modifies xen-blkback to unmap any domU page mapped via a
persistent grant after a timeout (default: 60 seconds). The timeout
is set to its default value again when a persistent grant has been
used for an I/O.

xen-blkfront is modified to scan every 10 seconds for persistent grants
not in use by blkback any more and to remove such grants.

The last 2 patches are small cleanups of blkfront and blkback drivers.

Juergen Gross (4):
  xen/blkback: don't keep persistent grants too long
  xen/blkfront: cleanup stale persistent grants
  xen/blkfront: reorder tests in xlblk_init()
  xen/blkback: remove unused pers_gnts_lock from struct xen_blkif_ring

 drivers/block/xen-blkback/blkback.c |  77 +++++++++++++++---------
 drivers/block/xen-blkback/common.h  |   2 +-
 drivers/block/xen-blkfront.c        | 115 ++++++++++++++++++++++++++++++++----
 3 files changed, 153 insertions(+), 41 deletions(-)

-- 
2.13.7


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-08-06 11:36 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-25  7:42 [PATCH] xen/blkfront: remove unused macros Juergen Gross
2018-07-25  9:30 ` Roger Pau Monné
2018-07-25 18:06 ` Jens Axboe
2018-08-06 11:33 [PATCH 0/4] xen/blk: persistent grant rework Juergen Gross
2018-08-06 11:34 ` [PATCH] xen/blkfront: remove unused macros Juergen Gross
2018-08-06 11:36   ` Juergen Gross

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