PROBE::IOBLOCK_TRACE

Section: IO Scheduler and block IO Taps (3stap)
Updated: August 2014
Index Return to Main Contents
 

NAME

probe::ioblock_trace.request - Fires just as a generic block I/O request is created for a bio.  

SYNOPSIS

ioblock_trace.request 
 

VALUES

None  

DESCRIPTION

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 device  

CONTEXT

The process makes block I/O request


 

Index

NAME
SYNOPSIS
VALUES
DESCRIPTION
CONTEXT

This document was created by man2html, using the manual pages.
Time: 23:19:55 GMT, August 08, 2014