The actual cache line size has always been 64 bytes.
The 128 number arose as an optimization for Core 2 era Intel processors. By
default (configurable in BIOS), these CPUs would prefetch adjacent cache
lines unintelligently. Newer CPUs prefetch more intelligently.
The latest Core 2 era CPU was introduced in September 2008 (Xeon 7400
series, "Dunnington"). If you are still using one of these CPUs, especially
in a multi-socket configuration, consider locating the "adjacent cache line
prefetch" option in BIOS and disabling it.
Reported by: mjg
Reviewed by: np
Discussed with: jhb
Sponsored by: Dell EMC Isilon
Before r207410, the hold count of a page in a page queue was protected
by the queue lock, and, before laundering a page, the page daemon
removed managed writeable mappings of the page before releasing the
queue lock. This ensured that other threads could not concurrently
create transient writeable mappings using pmap_extract_and_hold() on a
user map, as is done for example by vmapbuf(). With that revision,
however, a race can allow the creation of such a mapping, meaning that
the page might be modified as it is being laundered, potentially
resulting in it being marked clean when its contents do not match
those given to the pager. Close the race by using the page lock to
synchronize the hold count check in vm_pageout_cluster() with the
removal of writeable managed mappings.
Reported by: alc
Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D12084
according to the enabled interface capability bits. Also remove
some dead code, which tried to preserve already set contents of
E1000_WUC while that register is completely overwritten shortly
after in all cases.
FAT specification requires that for valid FAT, FAT cluster 0 has a
specific value derived from the BPB media descriptor. The lowest
(little-endian) byte must be equal to bpb.bpbMedia, other bits in the
cluster number must be all 1's. Implement the check to reduce the
chance of the randomly corrupted FAT to pass the mount attempt.
Submitted by: Siva Mahadevan <smahadevan@freebsdfoundation.org>
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D12124
This fixes interrupt storms on hardware using legacy level-triggered
interrupts, since doorbell processing could take time after interrupt
handler completion, that triggered extra interrupts in a loop.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Since the doorbell bit is already set when interrupt handler is called,
the event was not propagated to upper layer. It was working normally
because present code was not using masking actively, but that is going
to change.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
The old code allowed calling vdrop() before insmntque() to place the vnode back
onto the freelist for later recycling. Some downstream consumers may rely on
this support. Normally insmntque() failing is fine since is uses vgone() and
immediately frees the vnode rather than attempting to add it to the freelist if
vdrop() were used instead.
Also assert that vhold() cannot be used on such a vnode.
Reviewed by: kib, cem, markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12126
new use of the vm_object's lock to synchronize updates to a radix trie
mapping per-vm object page indices to on-disk swap blocks.
Fix a typo in a nearby comment.
Reviewed by: kib, markj
X-MFC with: r322913
Differential Revision: https://reviews.freebsd.org/D12134
vm_object page indices to on-disk swap space (r322913) has changed the
synchronization requirements for a couple swap pager functions. Whereas
before a read lock on the vm object sufficed because of the global mutex
on the hash table, a write lock on the vm object may now be required. In
particular, calls to vm_pager_page_unswapped() now require a write lock on
the vm_object. Consequently, vm_fault()'s fast path cannot call
vm_pager_page_unswapped(). The swap space will have to be released at a
later point.
Reviewed by: kib, markj
X-MFC with: r322913
Differential Revision: https://reviews.freebsd.org/D12134
This feature comes from the fact that we rely memory-backed md(4)
in our build process heavily. However, if the build goes haywire
the allocated resources (i.e. swap and memory-backed md(4)'s) need
to be purged. It is extremely useful to have ability to attach
arbitrary labels to each of the virtual disks so that they can
be identified and GC'ed if neecessary.
MFC after: 4 weeks
Differential Revision: https://reviews.freebsd.org/D10457
There were two bugs related to the blackhole detection:
* The smalles size was tried more than two times.
* The restored MSS was not the original one, but the second
candidate.
MFC after: 1 week
Sponsored by: Netflix, Inc.
GCC only activates C11 keywords in C mode, not C++ mode. This means
that when targeting an older C++ standard, we cannot fall back to using
_Static_assert(). In this case, do define _Static_assert() as a macro
that uses a typedef'ed array.
Discussed in: r322875 commit thread
Reported by: Mark MIllard
MFC after: 1 month
Decode fields from the siginfo_t stored in the PT_LWPINFO structure when a
signal is caught by a traced process. This includes the signal code
(si_code) as well as additional members such as si_addr, si_pid, etc.
Print the full conflicting oid path, and include the function name in the
warning so it is clear that the warnings are sysctl-related.
PR: 221853
Submitted by: Fabian Keil <fk AT fabiankeil.de> (earlier version)
Sponsored by: Dell EMC Isilon
This helps reduce the WORLDTMP footprint slightly.
Based on a patch I submitted 5 years ago to GNATS.
PR: 174051
MFC after: 2 weeks
Relnotes: yes (anyone who cross-builds with MK_TCSH=yes will run into
build failures if the host doesn't have tcsh(1))
Reminded by: Fabian Keil <fk@fabiankeil.de>
Tx power values can easily fit into uint8_t + only 8 bits are written
to registers; values may overflow only in case if ROM contains
malformed data (but limit is checked anyway).
Tested with RTL8188CUS, dev.rtwn.1.debug=0x2000 (no changes).
commit it to make initiazation less chatty in the normal case, and more useful
and informative when real debugging is turned on.
Reviewed by: ken (earlier version)
Sponsored by: Netflix
Improve scheduler performance by flattening nonsensical topology layers
(layers with only one child don't serve any purpose).
This is especially relevant on non-AMD Zen systems after r322776. On my
dual core Intel laptop, this brings the kern.sched.topology_spec table down
from three levels to two.
Submitted by: jeff
Reviewed by: attilio
Sponsored by: Dell EMC Isilon
Use efi_devpath_match instead of device_paths_match. They are
functionally the same. Remove device_paths_match from boot1.c and call
efi_devpath_match instead.
Sponsored by: Netflix
Kill our own hand-rolled (and somewhat flawed) devpath_str in favor of
the recently added efi_devpath_str in libefi. This gives us much
better names at the expense of not being able to debug on EFI 1.2
machines (since the UEFI protocol efi_devpath_str depends on was added
in UEFI 2.0). However, this isn't the first thing that requires newer
than EFI 1.2, so it's quite possible that this doesn't change the
universe of machines we can EFI boot from. This will now give us the
full UEFI path, even for devices we don't yet know about. More
importantly, it gives us the full HD(...) part of the path, which is
sufficient by itself to locate disks that follow the rules (dd one
disk (but not partition) to another still needs the rest of the path
to disambiguate, but that isn't following the rules that require every
GPT table to have globally unique GUIDs for every partion).
This also has the side effect of shrinking boot1.efi by ~3k.
Sponsored by: Netflix
Add libefi to the list of libraries we'll link in. Move EFI table
definitions back to libefi so we don't have drift between the two
efi_main routines.
Sponsored by: Netflix
Cast ctxp to caddr_t to pass data as expected. While void * is a
universal type, char * isn't (and that's what caddr_t is defined as).
One could argue these prototypes should take void * rather than
caddr_t, but changing that is much more invasive.
Sponsored by: Netflix
Make the return type of efi_main uniform. Declare the Exit() function
as not returning. Move efi_main's declaration to the proper header.
Sponsored by: Netflix
Move the efi_main routine out of libefi into sys/boot/efi/loader.
Since boot1 has its own efi_main routine, this effectively prevents
boot1 from linking with libefi. By moving it out, we can share code
better (though though some refactoring with boot1's efi_main and
loader.efi's efi_main is definitely in order).
Sponsored by: Netflix
Simplify i386 trap().
- Use more relevant name 'signo' instead of 'i' for the local variable
which contains a signal number to send for the current exception.
- Eliminate two labels 'userout' and 'out' which point to the very end
of the trap() function. Instead use return directly.
- Re-indent the prot_fault_translation block by reducing if() nesting.
- Some more monor style changes.
Reviewed by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The machdep.uprintf_signal sysctl replaced it in more convenient way,
not requiring recompilation to use and providing more information on
fault.
Reviewed by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
