Correct a bug when the number of pages for external mbufs was
very large. In this case the page number could overflow into the large
buffer flag. Make this more unlikley by move that flag further away.
This enable us to use /dev/fwmem* as a core file.
e.g.
ps -M /dev/fwmem0.0 -N kernel.debug
dmesg -M /dev/fwmem0.0 -N kernel.debug
gdb -k -c /dev/fwmem0.0 kernel.debug
You need to set target EUI64 in hw.firewire.fwmem.eui64_hi/lo before
opening the device. On the target arch, (PCI) bus address must be
equivalent to physical address.
(We cannot use this for sparc64 because of IOMMU.)
No objection in: -audit
is returned from the card to the driver. Add a counter that shows
how many times this allocation has failed. Note, that we could even
further delay the allocation of the mbuf until we know, that we need it
(there are no receive errors and the connection is open). This will be done
in a later commit.
Print the new statistics field in atmconfig.
atomic instructions instead. Remove the stuff used to track
whether an external mbuf travels through the system. This is
temporary only and will come back soon.
code has the typical branch prediction detour, which creates cross-
section branches. A LINT kernel is apparently large enough nowadays
that the .text and .text2 sections cannot always be layed-out so that
branches between them reach.
The fix is to stop using the alpha-specific bitops and instead use
the portable implementation used by all platforms other than alpha
and i386.
with an mbuf until it is reclaimed. This is in contrast to tags that
vanish when an mbuf chain passes through an interface. Persistent tags
are used, for example, by MAC labels.
Add an m_tag_delete_nonpersistent function to strip non-persistent tags
from mbufs and use it to strip such tags from packets as they pass through
the loopback interface and when turned around by icmp. This fixes problems
with "tag leakage".
Pointed out by: Jonathan Stone
Reviewed by: Robert Watson
send strhash(3) off to sleep with the fishes. Nothing in our tree uses it.
It has no documentation. It is nonstandard and in spite of the filename
strhash.c and strhash.h, it lives in application namespace by providing
compulsory global symbols hash_create()/hash_destroy()/hash_search()/
hash_traverse()/hash_purge()/hash_stats() regardless of whether you
#include <strhash.h> or not. If it turns out that there is a huge
application for this after all, I can repocopy it somewhere safer and
we can revive it elsewhere. But please, not in libc!
reset in a child process after a fork(). Currently, however, only the
real timer is cleared while the virtual and profiling timers are inherited.
The realtimer is cleared because it lives directly in struct proc in
p_realtimer. It is in the zero'd section of struct proc. The other timers
live in the p_timer[] array in struct pstats. These timers are copied on
fork() rather than zero'd. The fix is to move p_timer[] to the zero'd
part of struct pstats so that they are zero'd instead of copied on fork().
Note: Since at least FreeBSD 2.0 (and possibly earlier) we've had storage
for two real interval timers. Now that the uarea is less important,
perhaps we could move all of p_timer[] over to struct proc and drop the
p_realtimer special case to fix that.
PR: kern/58647
Reported by: Dan Nelson <dnelson@allantgroup.com>
MFC after: 1 week
the RNAT bit index constant. The net effect of this is that there's
no discontinuity WRT NaT collections which greatly simplifies certain
operations. The cost of this is that there can be up to 504 bytes of
unused stack between the true base of the kernel stack and the start
of the RSE backing store. The cost of adjusting the backing store
pointer to keep the RNAT bit index constant, for each kernel entry,
is negligible.
The primary reasons for this change are:
1. Asynchronuous contexts in KSE processes have the disadvantage of
having to copy the dirty registers from the kernel stack onto the
user stack. The implementation we had so far copied the registers
one at a time without calculating NaT collection values. A process
that used speculation would not work. Now that the RNAT bit index
is constant, we can block-copy the registers from the kernel stack
to the user stack without having to worry about NaT collections.
They will be in the right place on the user stack.
2. The ndirty field in the trapframe is now also usable in userland.
This was previously not the case because ndirty also includes the
space occupied by NaT collections. The value could be off by 8,
depending on the discontinuity. Now that the RNAT bit index is
contants, we have exactly the same number of NaT collection points
on the kernel stack as we would have had on the user stack if we
didn't switch backing stores.
3. Debuggers and other applications that use ptrace(2) can now copy
the dirty registers from the kernel stack (using ptrace(2)) and
copy them whereever they want them (onto the user stack of the
inferior as might be the case for gdb) without having to worry
about NaT collections in the same way the kernel doesn't have to
worry about them.
There's a second order effect caused by the randomization of the
base of the backing store, for it depends on the number of dirty
registers the processor happened to have at the time of entry into
the kernel. The second order effect is that the RSE will have a
better cache utilization as compared to having the backing store
always aligned at page boundaries. This has not been measured and
may be in practice only minimally beneficial, if at all measurable.
license. Only clause 3 has been revoked. Restore the fourth clause
as clause 3.
Pointed out by: das@
Remove my name as a copyright holder since I don't use a BSD license
compatible or comparable to the UCB license. I choose not to add a
complete second license for my work for aesthetic reasons, nor to
replace the UCB license on grounds of rewriting more than 90% of the
source files. The rewrite can also be seen as an enhancement and since
the files were practically empty, it's rather trivial to have changed
90% of the files.
