Unix and Linux Discussions Tagged with bios |
|
Thread / Thread Starter |
Last Post |
Replies |
Views |
Forum |
|
|
|
4 |
2,274 |
UNIX for Beginners Questions & Answers |
|
|
|
6 |
2,004 |
Programming |
|
|
|
11 |
9,780 |
Debian |
|
|
|
2 |
5,026 |
Solaris |
|
|
|
4 |
6,162 |
Red Hat |
|
|
|
1 |
1,956 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
19,180 |
Solaris |
|
|
|
6 |
3,820 |
Linux |
|
|
|
4 |
23,196 |
Solaris |
|
|
|
0 |
1,056 |
Software Releases - RSS News |
|
|
|
1 |
3,202 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
3,794 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
5,573 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
4,047 |
UNIX for Advanced & Expert Users |
|
|
|
1 |
4,089 |
UNIX for Dummies Questions & Answers |
|
|
|
1 |
3,387 |
UNIX for Dummies Questions & Answers |
|
|
|
1 |
2,780 |
UNIX for Advanced & Expert Users |
|
|
|
2 |
3,209 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
2,013 |
UNIX for Dummies Questions & Answers |
|
|
|
1 |
2,825 |
UNIX for Dummies Questions & Answers |
|
|
|
3 |
3,532 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
10,300 |
UNIX for Dummies Questions & Answers |
|
|
|
1 |
4,500 |
UNIX for Dummies Questions & Answers |
|
|
|
3 |
4,033 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
2,654 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
35,234 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
3,515 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
3,679 |
IP Networking |
|
|
|
1 |
3,504 |
UNIX for Dummies Questions & Answers |
BIO_ALLOC_BIOSET(9) The Linux VFS BIO_ALLOC_BIOSET(9)
NAME
bio_alloc_bioset - allocate a bio for I/O
SYNOPSIS
struct bio * bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set * bs);
ARGUMENTS
gfp_mask
the GFP_ mask given to the slab allocator
nr_iovecs
number of iovecs to pre-allocate
bs
the bio_set to allocate from.
DESCRIPTION
If bs is NULL, uses kmalloc to allocate the bio; else the allocation is backed by the bs's mempool.
When bs is not NULL, if __GFP_WAIT is set then bio_alloc will always be able to allocate a bio. This is due to the mempool guarantees. To
make this work, callers must never allocate more than 1 bio at a time from this pool. Callers that need to allocate more than 1 bio must
always submit the previously allocated bio for IO before attempting to allocate a new one. Failure to do so can cause deadlocks under
memory pressure.
Note that when running under generic_make_request (i.e. any block driver), bios are not submitted until after you return - see the code in
generic_make_request that converts recursion into iteration, to prevent stack overflows.
This would normally mean allocating multiple bios under generic_make_request would be susceptible to deadlocks, but we have deadlock
avoidance code that resubmits any blocked bios from a rescuer thread.
However, we do not guarantee forward progress for allocations from other mempools. Doing multiple allocations from the same mempool under
generic_make_request should be avoided - instead, use bio_set's front_pad for per bio allocations.
RETURNS
Pointer to new bio on success, NULL on failure.
COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 BIO_ALLOC_BIOSET(9)