OpenCloudOS-Kernel/drivers/scsi/bnx2fc
Neil Horman d576a5e80c bnx2fc: Improve stats update mechanism
Recently had this warning reported:

[  290.489047] Call Trace:
[  290.489053]  [<ffffffff8169efec>] dump_stack+0x19/0x1b
[  290.489055]  [<ffffffff810ac7a9>] __might_sleep+0x179/0x230
[  290.489057]  [<ffffffff816a4ad5>] mutex_lock_nested+0x55/0x520
[  290.489061]  [<ffffffffa01b9905>] ? bnx2fc_l2_rcv_thread+0xc5/0x4c0 [bnx2fc]
[  290.489065]  [<ffffffffa0174c1a>] fc_vport_id_lookup+0x3a/0xa0 [libfc]
[  290.489068]  [<ffffffffa01b9a6c>] bnx2fc_l2_rcv_thread+0x22c/0x4c0 [bnx2fc]
[  290.489070]  [<ffffffffa01b9840>] ? bnx2fc_vport_destroy+0x110/0x110 [bnx2fc]
[  290.489073]  [<ffffffff8109e0cd>] kthread+0xed/0x100
[  290.489075]  [<ffffffff8109dfe0>] ? insert_kthread_work+0x80/0x80
[  290.489077]  [<ffffffff816b2fec>] ret_from_fork+0x7c/0xb0
[  290.489078]  [<ffffffff8109dfe0>] ? insert_kthread_work+0x80/0x80

Its due to the fact that we call a potentially sleeping function from the bnx2fc
rcv path with preemption disabled (via the get_cpu call embedded in the per-cpu
variable stats lookup in bnx2fc_l2_rcv_thread.

Easy enough fix, we can just move the stats collection later in the function
where we are sure we won't preempt or sleep.  This also allows us to not have to
enable pre-emption when doing a per-cpu lookup, since we're certain not to get
rescheduled.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by:  Eddie Wai <eddie.wai@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-06-25 13:29:31 +02:00
..
57xx_hsi_bnx2fc.h New 7.0 FW: bnx2x, cnic, bnx2i, bnx2fc 2011-06-15 10:56:37 -04:00
Kconfig cnic: Fix select dependencies in bnx2fc/bnx2i Kconfig. 2011-08-12 03:00:47 -07:00
Makefile [SCSI] bnx2fc: Reduce object size by consolidating formats 2012-07-20 08:58:17 +01:00
bnx2fc.h [SCSI] bnx2fc: Updated version to 2.4.2 2014-03-15 10:17:47 -07:00
bnx2fc_constants.h cnic: Fix parity error code conflict 2012-03-21 21:57:36 -04:00
bnx2fc_debug.c [SCSI] bnx2fc: Reduce object size by consolidating formats 2012-07-20 08:58:17 +01:00
bnx2fc_debug.h [SCSI] bnx2fc: Reduce object size by consolidating formats 2012-07-20 08:58:17 +01:00
bnx2fc_els.c [SCSI] bnx2fc: Update copyright dates 2013-05-02 07:32:25 -07:00
bnx2fc_fcoe.c bnx2fc: Improve stats update mechanism 2014-06-25 13:29:31 +02:00
bnx2fc_hwi.c bnx2fc: fix memory leak in bnx2fc_allocate_hash_table() 2014-05-19 19:29:57 +02:00
bnx2fc_io.c bnx2fc: do not scan uninitialized lists in case of error. 2014-06-25 13:29:30 +02:00
bnx2fc_tgt.c SCSI misc on 20140401 2014-04-01 18:49:04 -07:00