On Mon, Dec 02, 2019 at 10:26:28PM -0500, Stephen Rust wrote: > > oops, it should have been (arg4 & 511) != 0. > > Yep, there they are: > > # /usr/share/bcc/tools/trace -K 'bio_add_page ((arg4 & 511) != 0) "%d > %d", arg3, arg4' > PID TID COMM FUNC - > 7411 7411 kworker/31:1H bio_add_page 512 76 > bio_add_page+0x1 [kernel] > sbc_execute_rw+0x28 [kernel] > __target_execute_cmd+0x2e [kernel] > target_execute_cmd+0x1c1 [kernel] > iscsit_execute_cmd+0x1e7 [kernel] > iscsit_sequence_cmd+0xdc [kernel] > isert_recv_done+0x780 [kernel] > __ib_process_cq+0x78 [kernel] > ib_cq_poll_work+0x29 [kernel] > process_one_work+0x179 [kernel] > worker_thread+0x4f [kernel] > kthread+0x105 [kernel] > ret_from_fork+0x1f [kernel] > > 7753 7753 kworker/26:1H bio_add_page 4096 76 The issue should be in brd_make_request() which assumes that bvec.bv_len is 512bytes align. I will figure out one patch for you tomorrow. Thanks, Ming
