From: Mike Christie <mchristi@redhat.com>
To: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com,
linux-scsi@vger.kernel.org, target-devel@vger.kernel.org,
nab@linux-iscsi.org
Cc: Mike Christie <mchristi@redhat.com>
Subject: [PATCH 15/19] tcmu: simplify dbi thresh handling
Date: Mon, 30 Oct 2017 03:44:35 +0000 [thread overview]
Message-ID: <1509335079-5276-16-git-send-email-mchristi@redhat.com> (raw)
In-Reply-To: <1509335079-5276-1-git-send-email-mchristi@redhat.com>
We do not really save a lot by trying to increase thresh
a multiple of the existing value. This just simplifies the
code by increasing it to whatever is needed for the command
being executed.
Signed-off-by: Mike Christie <mchristi@redhat.com>
---
drivers/target/target_core_user.c | 22 +++-------------------
1 file changed, 3 insertions(+), 19 deletions(-)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 68668a8..0630657 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -79,7 +79,6 @@
#define DATA_BLOCK_SIZE PAGE_SIZE
#define DATA_BLOCK_BITS (256 * 1024)
#define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE)
-#define DATA_BLOCK_INIT_BITS 128
/* The total size of the ring is 8M + 256K * PAGE_SIZE */
#define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
@@ -699,7 +698,6 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
if ((space * DATA_BLOCK_SIZE) < data_needed) {
unsigned long blocks_left = DATA_BLOCK_BITS - udev->dbi_thresh +
space;
- unsigned long grow;
if (blocks_left < blocks_needed) {
pr_debug("no data space: only %lu available, but ask for %zu\n",
@@ -708,23 +706,9 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
return false;
}
- /* Try to expand the thresh */
- if (!udev->dbi_thresh) {
- /* From idle state */
- uint32_t init_thresh = DATA_BLOCK_INIT_BITS;
-
- udev->dbi_thresh = max(blocks_needed, init_thresh);
- } else {
- /*
- * Grow the data area by max(blocks needed,
- * dbi_thresh / 2), but limited to the max
- * DATA_BLOCK_BITS size.
- */
- grow = max(blocks_needed, udev->dbi_thresh / 2);
- udev->dbi_thresh += grow;
- if (udev->dbi_thresh > DATA_BLOCK_BITS)
- udev->dbi_thresh = DATA_BLOCK_BITS;
- }
+ udev->dbi_thresh += blocks_needed;
+ if (udev->dbi_thresh > DATA_BLOCK_BITS)
+ udev->dbi_thresh = DATA_BLOCK_BITS;
}
return tcmu_get_empty_blocks(udev, cmd);
--
1.8.3.1
next prev parent reply other threads:[~2017-10-30 3:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-30 3:44 [PATCH 00/19] target/target_core_user: changes for 4.16 Mike Christie
2017-10-30 3:44 ` [PATCH 01/19] tcmu: fix crash when removing the tcmu device v4 Mike Christie
2017-10-30 3:44 ` [PATCH 02/19] tcmu: Add netlink command reply supported option for each device Mike Christie
2017-10-30 3:44 ` [PATCH 03/19] tcmu: Use macro to call container_of in tcmu_cmd_time_out_show Mike Christie
2017-10-30 3:44 ` [PATCH 04/19] tcmu: fix double se_cmd completion Mike Christie
2017-10-30 3:44 ` [PATCH 05/19] tcmu: merge common block release code Mike Christie
2017-10-30 3:44 ` [PATCH 06/19] tcmu: split unmap_thread_fn Mike Christie
2017-10-30 3:44 ` [PATCH 07/19] tcmu: fix unmap thread race Mike Christie
2017-10-30 3:44 ` [PATCH 08/19] tcmu: move expired command completion to unmap thread Mike Christie
2017-10-30 3:44 ` [PATCH 09/19] tcmu: remove commands_lock Mike Christie
2017-10-30 3:44 ` [PATCH 10/19] tcmu: release blocks for partially setup cmds Mike Christie
2017-10-30 3:44 ` [PATCH 11/19] tcmu: simplify scatter_data_area error handling Mike Christie
2017-10-30 3:44 ` [PATCH 12/19] tcmu: fix free block calculation Mike Christie
2017-10-30 3:44 ` [PATCH 13/19] tcmu: clean up the scatter helper Mike Christie
2017-10-30 3:44 ` [PATCH 14/19] tcmu: prep queue_cmd_ring to be used by unmap wq Mike Christie
2017-10-30 3:44 ` Mike Christie [this message]
2017-10-30 3:44 ` [PATCH 16/19] tcmu: don't block submitting context for block waits Mike Christie
2017-10-30 3:44 ` [PATCH 17/19] tcmu: make ring buffer timer configurable Mike Christie
2017-10-30 3:44 ` [PATCH 18/19] tcmu: allow max block and global max blocks to be settable Mike Christie
2017-10-30 3:44 ` [PATCH 19/19] target: return SAM_STAT_TASK_SET_FULL for TCM_OUT_OF_RESOURCES Mike Christie
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