Increase default ARC buf_hash_table size. When typical block size is small,
the hash table could be too small, which would lead to long hash chains and
limit performance for cached reads.
A new loader tunable, vfs.zfs.arc_average_blocksize, have been added which
allows users to override the default assumption of average (typical) block
size. Old default was 65536 (64 KiB) and new default is 8192 (8 KiB).
Illumos issue:
5034 ARC's buf_hash_table is too small
MFC after: 2 weeks
Change dn->dn_dbufs from linked list to AVL tree.
Illumos issues:
4873 zvol unmap calls can take a very long time for larger datasets
MFC after: 2 weeks
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Approved by: Gordon Ross <gwr@nexenta.com>
illumos/illumos-gate@63e911b6fc
code behave more like it is on Solaris.
Reported by: avg
Reviewed by: avg, mav (but bugs are mine)
Differential Revision: https://phabric.freebsd.org/D457
moved from the stack into the tag structure. In retrospect that was a bad
idea, because nothing protects that array from concurrent access by
multiple threads.
This change moves the array to the map structure (actually it's allocated
following the structure, but all in a single malloc() call).
This also establishes a "sane" limit of 4096 segments per map. This is
mostly to prevent trying to allocate all of memory if someone accidentally
uses a tag with nsegments set to BUS_SPACE_UNRESTRICTED. If there's ever
a genuine need for more than 4096, don't hesitate to increase this (or
maybe make it tunable).
Reviewed by: cognet
triggers a need to bounce due to cacheline alignment. These buffers
are always aligned to cacheline boundaries, and even when the DMA operation
starts at an offset within the buffer or doesn't extend to the end of the
buffer, it's safe to flush the complete cachelines that were only partially
involved in the DMA. This is because there's a very strict rule on these
types of buffers that there will not be concurrent access by the CPU and
one or more DMA transfers within the buffer.
Reviewed by: cognet
functions, it has evolved to make a variety of decisions about whether
the DMA needs to bounce, so rename it to must_bounce(). Rewrite it to
perform checks outside of the ancestor loop if they're based on information
that's wholly contained within the original tag. Now the loop only checks
exclusion zones in ancestor tags.
Also, add a new function, might_bounce() which does a fast inline check
of flags within the tag and map to quickly eliminate the need to call
the more expensive must_bounce() for each page in the DMA operation.
Within the mapping loops, use map->pagesneeded != 0 as a proxy for all
the various checks on whether bouncing might be required. If no pages
were reserved for bouncing during the checks before the mapping loop,
then there's no need to re-check any of the conditions that can lead
to bouncing -- all those checks already decided there would be no bouncing.
Reviewed by: cognet
exclusion zones and phsyical memory. The phys_avail[i] entries are the
address of the first byte of ram in the region, and phys_avail[i+1]
entries are the address of the first byte of ram in the next region
(i.e., they're not included in the region that starts at phys_avail[i]).
Reviewed by: cognet
unchanging values in the phys_avail array, so do the comparisons just once
at tag creation time and set a flag to remember the result.
Reviewed by: cognet
DMA on arm can bounce for several reasons, and _bus_dma_can_bounce() only
checks for the lowaddr/highaddr exclusion ranges in the dma tag, so now
it's named exclusion_bounce(). The other reasons for bouncing are checked
by the new functions alignment_bounce() and cacheline_bounce().
Reviewed by: cognet
requires the return value of telldir() to equal the value passed to
seekdir(). The current seekdir code with SINGLEUSE enabled breaks
this case as each call to telldir() allocates a new cookie. Instead,
remove the SINGLEUSE code and change telldir() to look for an existing
cookie for the directory's current location rather than always creating
a new cookie.
CR: https://phabric.freebsd.org/D490
PR: 121656
Reviewed by: jilles
MFC after: 1 week
postponing it to zfs_vget(). zfs_root() returned vnode with the
default value of v_hash, which caused inconsistent v_hash value when
root vnode was obtained from zfs_vget().
Nullfs allocated two upper vnodes for the root zfs vnode due to
different hashes, causing consistency problems.
Reported and tested by: Harald Schmalzbauer <h.schmalzbauer@omnilan.de>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
ping6(8) would quit before the remote side gets a chance to respond.
Solve this by resetting the itimer when we have reached the maximum packet
number have reached, but let the other handling to continue.
PR: bin/151023
Submitted by: tjmao at tjmao.net
MFC after: 2 weeks
