the pipe is locked and shouldn't be.
initialize pipe->pipe_mtxp to NULL when creating pipes in order not
to trip the above assertions.
swap pipe lock with giant around calls to pipe_destroy_write_buffer()
pipe_destroy_write_buffer issue noticed by: jhb
fully protect p_ucred yet so Giant is needed until all the p_ucred
locking is done. This is the original reason td_ucred was not used
immediately after its addition. Unfortunately, not using td_ucred is
not enough to avoid problems. Since p_ucred could be stale, we could
actually be dereferencing a stale pointer to dink with the refcount, so
we really need Giant to avoid foot-shooting. This allows td_ucred to
be safely used as well.
In order to determine what to page out, the vm_daemon checks
reference bits on all pages belonging to all processes. Unfortunately,
the algorithm used reacted badly with shared pages; each shared page
would be checked once per process sharing it; this caused an O(N^2)
growth of tlb invalidations. The algorithm has been changed so that
each page will be checked only 16 times.
Prior to this change, a fork/sleepbomb of 1300 processes could cause
the vm_daemon to take over 60 seconds to complete, effectively
freezing the system for that time period. With this change
in place, the vm_daemon completes in less than a second. Any system
with hundreds of processes sharing pages should benefit from this change.
Note that the vm_daemon is only run when the system is under extreme
memory pressure. It is likely that many people with loaded systems saw
no symptoms of this problem until they reached the point where swapping
began.
Special thanks go to dillon, peter, and Chuck Cranor, who helped me
get up to speed with vm internals.
PR: 33542, 20393
Reviewed by: dillon
MFC after: 1 week
in most machines of the Sun Ultra series. This is a port of the NetBSD
driver which I enhanced to make use of the gather functionality and the
configurable RX buffer offset to avoid copying all received/sent packet
(instead, packets will be directly DMAd from mbuf chains and into mbuf
clusters now).
device drivers for bus system with other endinesses than the CPU (using
interfaces compatible to NetBSD):
- bwap16() and bswap32(). These have optimized implementations on some
architectures; for those that don't, there exist generic implementations.
- macros to convert from a certain byte order to host byte order and vice
versa, using a naming scheme like le16toh(), htole16().
These are implemented using the bswap functions.
- stream bus space access functions, which do not perform a byte order
conversion (while the normal access functions would if the bus endianess
differs from the CPU endianess).
htons(), htonl(), ntohs() and ntohl() are implemented using the new
functions above for kernel usage. None of the above interfaces is currently
exported to user land.
Make use of the new functions in a few places where local implementations
of the same functionality existed.
Reviewed by: mike, bde
Tested on alpha by: mike
as arguments. The correct hostname is copied into the buffer
while having the prison's lock acquired in a jailed process'
case.
Reviewed by: jhb, rwatson
2) Don't compile vendor ID.
3) WARNS=4 fixes (constness, make a global local to avoid shadowing, unused
parameters, rename local to avoid shadowing, remove junk after #endif)
4) remove some "register"s.
2) Cast some numbers we know to be positive to size_t before we MIN them
with the result of a sizeof.
3) Compare result of inet_addr to INADDR_NONE, not -1.
There is some unresolved badness that has been eluding me, particularly
affecting uniprocessor kernels. Turning off PG_G helped (which is a bad
sign) but didn't solve it entirely. Userland programs still crashed.
1/ conditionalise (#if 0) function that is not used.
Unused code left in place for netBSD compatibility.
2/ Recode loop to convince gcc that it does initialise a variable
(use do-while instead of for() so gcc knows that we always go through
at least once. Feel free to check my logic.
Both ends of the pipe share a pool_mutex, this makes allocation
and deadlock avoidance easy.
Remove some un-needed FILE_LOCK ops while I'm here.
There are some issues wrt to select and the f{s,g}etown code that
we'll have to deal with, I think we may also need to move the calls
to vfs_timestamp outside of the sections covered by PIPE_LOCK.
work loads. It tapers off after that as gcc's working set generally just fits.
compiling bin/csh:
TSB_PAGES = 2
213.33 real 77.59 user 110.01 sys
TSB_PAGES = 4
116.43 real 75.78 user 19.16 sys
TSB_PAGES = 8
119.27 real 76.38 user 18.12 sys
Testing by: tmm
