mirror_zfs/cmd/raidz_test
Matthew Ahrens e2af2acce3
allow callers to allocate and provide the abd_t struct
The `abd_get_offset_*()` routines create an abd_t that references
another abd_t, and doesn't allocate any pages/buffers of its own.  In
some workloads, these routines may be called frequently, to create many
abd_t's representing small pieces of a single large abd_t.  In
particular, the upcoming RAIDZ Expansion project makes heavy use of
these routines.

This commit adds the ability for the caller to allocate and provide the
abd_t struct to a variant of `abd_get_offset_*()`.  This eliminates the
cost of allocating the abd_t and performing the accounting associated
with it (`abdstat_struct_size`).  The RAIDZ/DRAID code uses this for
the `rc_abd`, which references the zio's abd.  The upcoming RAIDZ
Expansion project will leverage this infrastructure to increase
performance of reads post-expansion by around 50%.

Additionally, some of the interfaces around creating and destroying
abd_t's are cleaned up.  Most significantly, the distinction between
`abd_put()` and `abd_free()` is eliminated; all types of abd_t's are
now disposed of with `abd_free()`.

Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Issue #8853 
Closes #11439
2021-01-20 11:24:37 -08:00
..
.gitignore SIMD implementation of vdev_raidz generate and reconstruct routines 2016-06-21 09:27:26 -07:00
Makefile.am Unconditionally enable debugging for libzpool 2020-07-10 15:30:31 -07:00
raidz_bench.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
raidz_test.c allow callers to allocate and provide the abd_t struct 2021-01-20 11:24:37 -08:00
raidz_test.h Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00