diff options
| author | Ming Lei <ming.lei@redhat.com> | 2017-07-05 12:14:27 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-07-05 12:11:26 -0600 |
| commit | 8a05aa4ce3bf767b7bd72851da89c23d084d1ecb (patch) | |
| tree | 2ad465f735488c668d1193d02c066ba3f3b00863 /drivers/block | |
| parent | ea4d12dabf872b496218cdc8e7874feef8676cdd (diff) | |
| download | linux-8a05aa4ce3bf767b7bd72851da89c23d084d1ecb.tar.bz2 | |
mtip32xx: avoid to read HOST_CAP from HW in .queue_rq()
It is observed reading the register from HW takes a bit long,
for example in my box, the following difference of 'perf report
--no-children fio ...' can be seen when running I/O:
1) V4.12 without patch
+ 9.28% fio [mtip32xx] [k] mtip_irq_handler
+ 8.48% fio [mtip32xx] [k] mtip_init_cmd_header
2) V4.12 with the following patch
+ 9.14% fio [mtip32xx] [k] mtip_irq_handler
......
+ 1.14% fio [mtip32xx] [k] mtip_init_cmd_header
IOPS can be increased by ~5% with this patch too.
Fixes: a4e84aae8139(mtip32xx: use runtime tag to initialize command header)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/mtip32xx/mtip32xx.c | 4 | ||||
| -rw-r--r-- | drivers/block/mtip32xx/mtip32xx.h | 1 |
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c index 61b046f256ca..ae910347b7cf 100644 --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -174,7 +174,6 @@ static void mtip_init_cmd_header(struct request *rq) { struct driver_data *dd = rq->q->queuedata; struct mtip_cmd *cmd = blk_mq_rq_to_pdu(rq); - u32 host_cap_64 = readl(dd->mmio + HOST_CAP) & HOST_CAP_64; /* Point the command headers at the command tables. */ cmd->command_header = dd->port->command_list + @@ -182,7 +181,7 @@ static void mtip_init_cmd_header(struct request *rq) cmd->command_header_dma = dd->port->command_list_dma + (sizeof(struct mtip_cmd_hdr) * rq->tag); - if (host_cap_64) + if (test_bit(MTIP_PF_HOST_CAP_64, &dd->port->flags)) cmd->command_header->ctbau = __force_bit2int cpu_to_le32((cmd->command_dma >> 16) >> 16); cmd->command_header->ctba = __force_bit2int cpu_to_le32(cmd->command_dma & 0xFFFFFFFF); @@ -386,6 +385,7 @@ static void mtip_init_port(struct mtip_port *port) port->mmio + PORT_LST_ADDR_HI); writel((port->rxfis_dma >> 16) >> 16, port->mmio + PORT_FIS_ADDR_HI); + set_bit(MTIP_PF_HOST_CAP_64, &port->flags); } writel(port->command_list_dma & 0xFFFFFFFF, diff --git a/drivers/block/mtip32xx/mtip32xx.h b/drivers/block/mtip32xx/mtip32xx.h index e8286af50e16..e20e55dab443 100644 --- a/drivers/block/mtip32xx/mtip32xx.h +++ b/drivers/block/mtip32xx/mtip32xx.h @@ -140,6 +140,7 @@ enum { (1 << MTIP_PF_SE_ACTIVE_BIT) | (1 << MTIP_PF_DM_ACTIVE_BIT) | (1 << MTIP_PF_TO_ACTIVE_BIT)), + MTIP_PF_HOST_CAP_64 = 10, /* cache HOST_CAP_64 */ MTIP_PF_SVC_THD_ACTIVE_BIT = 4, MTIP_PF_ISSUE_CMDS_BIT = 5, |