mappings required by mdstart_swap(). On i386, if the ephemeral mapping
is already in the sf_buf mapping cache, a swap-backed md performs
similarly to a malloc-backed md. Even if the ephemeral mapping is not
cached, this implementation is still faster. On 64-bit platforms, this
change has the effect of using the direct virtual-to-physical mapping,
avoiding ephemeral mapping overheads, such as TLB shootdowns on SMPs.
On a 2.4GHz, 400MHz FSB P4 Xeon configured with 64K sf_bufs and
"mdmfs -S -o async -s 128m md /mnt"
before:
dd if=/dev/md0 of=/dev/null bs=64k
134217728 bytes transferred in 0.430923 secs (311465697 bytes/sec)
after with cold sf_buf cache:
dd if=/dev/md0 of=/dev/null bs=64k
134217728 bytes transferred in 0.367948 secs (364773576 bytes/sec)
after with warm sf_buf cache:
dd if=/dev/md0 of=/dev/null bs=64k
134217728 bytes transferred in 0.252826 secs (530870010 bytes/sec)
malloc-backed md:
dd if=/dev/md0 of=/dev/null bs=64k
134217728 bytes transferred in 0.253126 secs (530240978 bytes/sec)
I've added -fno-strict-aliasing for now so we can ease into this.
I wanted to shoot for -O3, but the inlining caused problems due to GCC's
size heuristics; so also add -frename-registers, which is one of the things
-O3 would have given us.
entry size and the ELF version. Also, avoid a potential integer
overflow when determining whether the ELF header fits entirely
within the first page.
Reviewed by: jdp
A panic when attempting to execute an ELF binary with a bogus program
header table entry size was
Reported by: Christer Öberg <christer.oberg@texonet.com>
the tap driver, even with Giant over the cdev operation vector, due to
a non-atomic test-and-set of the si_drv1 field in the dev_t. This bug
exists with Giant under high memory pressure, as malloc() may sleep
in tapcreate(), but is less likely to occur. The resolution will
probably be to cover si_drv1 using the global tapmtx since no softc is
available, but I need to think about this problem more generally
across a range of drivers using si_drv1 in combination with SI_CHEAPCLONE
to defer expensive allocation to open().
Correct what appears to be a bug in the original if_tap implementation,
in which tapopen() will panic if a tap device instance is opened more
than once due to an incorrect assertion -- only triggered if INVARIANTS
is compiled in (i.e., when built into a kernel). Return EBUSY instead.
Expand mtx_lock() coverage using tp->tap_mtx to include tp->ether_addr.
- 0 should have been -1 in previous commit (just to stay consistent),
- Spell null pointers as NULL, not 0,
- Fixed the comment about pr_usesysctl to not confuse it with boolean.
Pointed by: bde
use sf_buf_free() instead of sf_buf_mext() to consolidate all actions
that require the page queues lock in one critical section. While I'm
here remove unnecessary splvm() and splx() calls.
just print the header (if any) and exit, thus matching the behavior on -stable
and other OS's.
Also adds support for <x> being a comma-separated list of processes, and does
a much better checking for invalid-values of <x>, such as 'ps -p someword'.
Reviewed by: mentioned on freebsd-current
MFC after: 10 days
clip/destroy the dB value contained in the wi(4)'s receive frames,
it doesn't match with the flag set in the radiotap header
(unperturbed dB versus dBm).
Also set HOOK_HACK to true (remove the related #ifdef's) as we have the
hooks in the kernel this was missed during the merge from the port.
Noticed by: Amir S. (for the HOOK_HACK part)
Approved by: bms(mentor)
options, status pointer and rusage pointer as arguments. It is up to
the caller to copyout the status and rusage to userland if needed. This
lets us axe the 'compat' argument and hide all that functionality in
owait(), by the way. This also cleans up some locking in kern_wait()
since it no longer has to drop locks around copyout() since all the
copyout()'s are deferred.
- Convert owait(), wait4(), and the various ABI compat wait() syscalls to
use kern_wait() rather than wait1() or wait4(). This removes a bit
more stackgap usage.
Tested on: i386
Compiled on: i386, alpha, amd64
