table of contents
other versions
- wheezy 1.7-1+deb7u1
- jessie 2.6-0.2
- jessie-backports 3.0-6~bpo8+1
- testing 3.1-2
- unstable 3.1-2
PROBE::IO(3stap) | IO Scheduler and block IO Taps | PROBE::IO(3stap) |
probe::ioblock_trace.request
NAME¶
probe::ioblock_trace.request - Fires just as a generic block I/O request is created for a bio.SYNOPSIS¶
ioblock_trace.request
VALUES¶
NoneDESCRIPTION¶
name - name of the probe point q - request queue on which this bio was queued. devname - block device name ino - i-node number of the mapped file bytes_done - number of bytes transferred sector - beginning sector for the entire bio flags - see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1 RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user pages BIO_EOPNOTSUPP 7 not supported rw - binary trace for read/write request vcnt - bio vector count which represents number of array element (page, offset, length) which make up this I/O request idx - offset into the bio vector array phys_segments - number of segments in this bio after physical address coalescing is performed. size - total size in bytes bdev - target block device bdev_contains - points to the device object which contains the partition (when bio structure represents a partition) p_start_sect - points to the start sector of the partition structure of the deviceCONTEXT¶
The process makes block I/O requestMay 2013 | SystemTap Tapset Reference |