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| author | Matthew Wilcox | 2018-06-12 21:05:44 +0200 |
|---|---|---|
| committer | Martin K. Petersen | 2018-06-20 04:02:25 +0200 |
| commit | 10e9cbb6b531117be0c4a79f2c7fa9a45a0dd532 (patch) | |
| tree | ea333b10d3aa71849264ab3fe6147b0e0d4420da /drivers/usb | |
| parent | scsi: target: Abstract tag freeing (diff) | |
| download | kernel-qcow2-linux-10e9cbb6b531117be0c4a79f2c7fa9a45a0dd532.tar.gz kernel-qcow2-linux-10e9cbb6b531117be0c4a79f2c7fa9a45a0dd532.tar.xz kernel-qcow2-linux-10e9cbb6b531117be0c4a79f2c7fa9a45a0dd532.zip | |
scsi: target: Convert target drivers to use sbitmap
The sbitmap and the percpu_ida perform essentially the same task,
allocating tags for commands. The sbitmap outperforms the percpu_ida as
documented here: https://lkml.org/lkml/2014/4/22/553
The sbitmap interface is a little harder to use, but being able to remove
the percpu_ida code and getting better performance justifies the additional
complexity.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> # f_tcm
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/gadget/function/f_tcm.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c index 9f670d9224b9..5003e857dce7 100644 --- a/drivers/usb/gadget/function/f_tcm.c +++ b/drivers/usb/gadget/function/f_tcm.c @@ -1071,15 +1071,16 @@ static struct usbg_cmd *usbg_get_cmd(struct f_uas *fu, { struct se_session *se_sess = tv_nexus->tvn_se_sess; struct usbg_cmd *cmd; - int tag; + int tag, cpu; - tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); + tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); if (tag < 0) return ERR_PTR(-ENOMEM); cmd = &((struct usbg_cmd *)se_sess->sess_cmd_map)[tag]; memset(cmd, 0, sizeof(*cmd)); cmd->se_cmd.map_tag = tag; + cmd->se_cmd.map_cpu = cpu; cmd->se_cmd.tag = cmd->tag = scsi_tag; cmd->fu = fu; |