retransmitted mbufs can survive even after requests themselves
finished. so, before unbusy pages, make sure that mbufs referring them
go away.
pointed by enami tsugutomo on port-mips.
instead of "struct vnode". This saves a number of pointer dereferences;
it sums up to about half a kB for me. And it paves the way for future
fixes.
While cleaning up, eliminate a write-only member of "struct nfsreq"
and a pointless assignment in the NFS_V2_ONLY case.
Do a little mbuf rework while here. Change all uses of MGET*(*, M_WAIT, *)
to m_get*(M_WAIT, *). These are not performance critical and making them
call m_get saves considerable space. Add m_clget analogue of MCLGET and
make corresponding change for M_WAIT uses.
Modify netinet, gem, fxp, tulip, nfs to support MBUFTRACE.
Begin to change netstat to use sysctl.
kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals
kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)
based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe
add a flag that specify if the file can be truncated safely or not
to nfsm_loadattr and friends. when it isn't safe, just mark the nfsnode
as "should be truncated later".
ok'ed by Frank van der Linden and Chuck Silvers.
close kern/18036.
and confusion about the actual filesize. From Matt Dillon's
similar change in FreeBSD.
XXX n_size is really redundant in -current and must die. This commit
XXX is more of a placeholder for a pullup into the 1.5 branch.
uint32_t namei_hash(const char *p, const char **ep)
which determines the equivalent MI hash32_str() hash for p.
If *ep != NULL, calculate the hash to the character before ep.
If *ep == NULL, calculate the has to the first / or NUL found, and
point *ep to that location.
- Use namei_hash() to calculate cn_hash in lookup() and relookup().
Hash distribution goes from 35-40% to 55-70%, with similar profiled
time spent in cache_lookup() and cache_enter() on my P3-600.
- Use namei_hash() to calculate cn_hash in nfs_readdirplusrpc(),
insetad of homegrown code (that differed from that in lookup() !)
namei_hash() has better spread and is faster than previous code
(which used a non-constant multiplication).
- remove special treatment of pager_map mappings in pmaps. this is
required now, since I've removed the globals that expose the address range.
pager_map now uses pmap_kenter_pa() instead of pmap_enter(), so there's
no longer any need to special-case it.
- eliminate struct uvm_vnode by moving its fields into struct vnode.
- rewrite the pageout path. the pager is now responsible for handling the
high-level requests instead of only getting control after a bunch of work
has already been done on its behalf. this will allow us to UBCify LFS,
which needs tighter control over its pages than other filesystems do.
writing a page to disk no longer requires making it read-only, which
allows us to write wired pages without causing all kinds of havoc.
- use a new PG_PAGEOUT flag to indicate that a page should be freed
on behalf of the pagedaemon when it's unlocked. this flag is very similar
to PG_RELEASED, but unlike PG_RELEASED, PG_PAGEOUT can be cleared if the
pageout fails due to eg. an indirect-block buffer being locked.
this allows us to remove the "version" field from struct vm_page,
and together with shrinking "loan_count" from 32 bits to 16,
struct vm_page is now 4 bytes smaller.
- no longer use PG_RELEASED for swap-backed pages. if the page is busy
because it's being paged out, we can't release the swap slot to be
reallocated until that write is complete, but unlike with vnodes we
don't keep a count of in-progress writes so there's no good way to
know when the write is done. instead, when we need to free a busy
swap-backed page, just sleep until we can get it busy ourselves.
- implement a fast-path for extending writes which allows us to avoid
zeroing new pages. this substantially reduces cpu usage.
- encapsulate the data used by the genfs code in a struct genfs_node,
which must be the first element of the filesystem-specific vnode data
for filesystems which use genfs_{get,put}pages().
- eliminate many of the UVM pagerops, since they aren't needed anymore
now that the pager "put" operation is a higher-level operation.
- enhance the genfs code to allow NFS to use the genfs_{get,put}pages
instead of a modified copy.
- clean up struct vnode by removing all the fields that used to be used by
the vfs_cluster.c code (which we don't use anymore with UBC).
- remove kmem_object and mb_object since they were useless.
instead of allocating pages to these objects, we now just allocate
pages with no object. such pages are mapped in the kernel until they
are freed, so we can use the mapping to find the page to free it.
this allows us to remove splvm() protection in several places.
The sum of all these changes improves write throughput on my
decstation 5000/200 to within 1% of the rate of NetBSD 1.5
and reduces the elapsed time for "make release" of a NetBSD 1.5
source tree on my 128MB pc to 10% less than a 1.5 kernel took.
if we do this for VBLK vnodes which are in use by softdep mounts,
brelse() will mark the buffer B_INVAL as well, which makes the
softdep code very unhappy.
