This allows accton(1) to be used with an append-only file.
PR: 7169
Reported by: Joao Carlos Mendes Luis <jonny@jonny.eng.br>
Reviewed by: bde
Approved by: sheldonh (mentor)
MFC after: 2 weeks
methodology similar to the vm_map_entry splay and the VM splay that Alan
Cox is working on. Extensive testing has appeared to have shown no
increase in overhead.
Disadvantages
Dirties more cache lines during lookups.
Not as fast as a hash table lookup (but still N log N and optimal
when there is locality of reference).
Advantages
vnode->v_dirtyblkhd is now perfectly sorted, making fsync/sync/filesystem
syncer operate more efficiently.
I get to rip out all the old hacks (some of which were mine) that tried
to keep the v_dirtyblkhd tailq sorted.
The per-vnode splay tree should be easier to lock / SMPng pushdown on
vnodes will be easier.
This commit along with another that Alan is working on for the VM page
global hash table will allow me to implement ranged fsync(), optimize
server-side nfs commit rpcs, and implement partial syncs by the
filesystem syncer (aka filesystem syncer would detect that someone is
trying to get the vnode lock, remembers its place, and skip to the
next vnode).
Note that the buffer cache splay is somewhat more complex then other splays
due to special handling of background bitmap writes (multiple buffers with
the same lblkno in the same vnode), and B_INVAL discontinuities between the
old hash table and the existence of the buffer on the v_cleanblkhd list.
Suggested by: alc
- Remove some obsolete code (NetBSD gem.c r1.12)
- Clean up how the local MAC address is programmed (NetBSD gem.c r1.13)
- Make the driver work on PowerMacs with gigabit interfaces
(NetBSD gem.c r1.14 and r1.15, gemreg.h r1.3 and r1.4, gemvar.h r1.6 and 1.7)
- Suppress RX_MAC interrutps regarding the FRAME_COUNT register.
(NetBSD gem.c r1.16 and r1.17)
- Fix receiver lockups. (NetBSD gem.c r1.18, gemvar.h r1.8)
- Distinguish between Apple and Sun variants (NetBSD if_gem_pci.c r1.9)
Reviewed by: tmm
Obtained from: NetBSD
like this can be emulated by VT_SETMODEing to VT_PROCESS and never
releasing the vty, but this has a number of problems, most notably
that a process must stay resident for the lock to be in effect.
Reviewed by: roam, sheldonh
ipl.s except doreti which really belongs in with the exceptions as it's
just the other side of the same coin. Will remove ipl.s in a separate commit.
Agreed by: several including bde@freebsd.org
- Add IGNORE_LOCK() that only ignores VCHR files for now since no one locks
their underlying device in the leaf filesystems. (devvp)
- Add prototypes for vop_lookup_{pre,post} that I forgot before.
