TRACE_BLOCK_BIO_BACK(9) Block IO TRACE_BLOCK_BIO_BACK(9)NAME
trace_block_bio_backmerge - merging block operation to the end of an existing operation
void trace_block_bio_backmerge(struct request_queue * q, struct request * rq, struct bio * bio);
queue holding operation
request bio is being merged into
new block operation to merge
Merging block request bio to the end of an existing block request in queue q.
Jason Baron <firstname.lastname@example.org>
William Cohen <email@example.com>
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 TRACE_BLOCK_BIO_BACK(9)
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PROBE::IOBLOCK.REQ(3stap) IO Scheduler and block IO Taps PROBE::IOBLOCK.REQ(3stap)NAME
probe::ioblock.request - Fires whenever making a generic block I/O request.
name - name of the probe point devname - block device name ino - i-node number of the mapped file 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 hw_segments - number of segments after physical and DMA remapping hardware 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
The process makes block I/O request
SystemTap Tapset Reference June 2014 PROBE::IOBLOCK.REQ(3stap)
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