should_yield(). Use this in various places. Encapsulate the common
case of check-and-yield into a new function maybe_yield().
Change several checks for a magic number of iterations to use
should_yield() instead.
MFC after: 1 week
sf buf allocation, use wakeup() instead of wakeup_one() to notify sf
buffer waiters about free buffer.
sf_buf_alloc() calls msleep(PCATCH) when SFB_CATCH flag was given,
and for simultaneous wakeup and signal delivery, msleep() returns
EINTR/ERESTART despite the thread was selected for wakeup_one(). As
result, we loose a wakeup, and some other waiter will not be woken up.
Reported and tested by: az
Reviewed by: alc, jhb
MFC after: 1 week
Compile sys/dev/mem/memutil.c for all supported platforms and remove now
unnecessary dev_mem_md_init(). Consistently define mem_range_softc from
mem.c for all platforms. Add missing #include guards for machine/memdev.h
and sys/memrange.h. Clean up some nearby style(9) nits.
MFC after: 1 month
TSB is located within the 32-bit address space, which held true as long as
we were using virtual addresses magic-mapped before the location of the
kernel for addressing it. However, with r216803 in place when possible we
address it via its physical address instead, which on machines like Sun Fire
V880 have no physical memory in the 32-bit address space at all requires
to use 64-bit addressing. When using physical addressing it still should
be safe to assume that we can just ignore the lowest 10 bits of the address
as a minor optimization as we did before r216803.
architecture macros (__mips_n64, __powerpc64__) when 64 bit types (and
corresponding macros) are different from 32 bit. [1]
Correct the type of INT64_MIN, INT64_MAX and UINT64_MAX.
Define (U)INTMAX_C as an alias for (U)INT64_C matching the type definition
for (u)intmax_t. Do this on all architectures for consistency.
Suggested by: bde [1]
Approved by: kib (mentor)
On some architectures UCHAR_MAX and USHRT_MAX had type unsigned int.
However, lacking integer suffixes for types smaller than int, their type
should correspond to that of an object of type unsigned char (or short)
when used in an expression with objects of type int. In that case unsigned
char (short) are promoted to int (i.e. signed) so the type of UCHAR_MAX and
USHRT_MAX should also be int.
Where MIN/MAX constants implicitly have the correct type the suffix has
been removed.
While here, correct some comments.
Reviewed by: bde
Approved by: kib (mentor)
and switch sparc64 to use the first one for bus error filter handlers of
bridge drivers instead of (ab)using INTR_FAST for that so we eventually
can get rid of the latter.
Reviewed by: jhb
MFC after: 1 month
functions, otherwise if we get preempted after checking whether a certain
pmap is active on the current CPU but before disabling interrupts we might
operate on an outdated state as the pmap might have been deactivated in
the meantime. As the same issue may arises when the TLB demap function is
interrupted by a TLB demap IPI, just entering a critical section before
the check isn't sufficient so we have to fully disable interrupts instead.
MFC after: 3 days
which takes an physical address instead of an virtual one, for loading TTEs
of the kernel TSB so we no longer need to lock the kernel TSB into the dTLB,
which only has a very limited number of lockable dTLB slots. The net result
is that we now basically can handle a kernel TSB of any size and no longer
need to limit the kernel address space based on the number of dTLB slots
available for locked entries. Consequently, other parts of the trap handlers
now also only access the the kernel TSB via its physical address in order
to avoid nested traps, as does the PMAP bootstrap code as we haven't taken
over the trap table at that point, yet. Apart from that the kernel TSB now
is accessed via a direct mapping when we are otherwise taking advantage of
ASI_ATOMIC_QUAD_LDD_PHYS so no further code changes are needed. Most of this
is implemented by extending the patching of the TSB addresses and mask as
well as the ASIs used to load it into the trap table so the runtime overhead
of this change is rather low. Currently the use of ASI_ATOMIC_QUAD_LDD_PHYS
is not yet enabled on SPARC64 CPUs due to lack of testing and due to the
fact it might require minor adjustments there.
Theoretically it should be possible to use the same approach also for the
user TSB, which already is not locked into the dTLB, avoiding nested traps.
However, for reasons I don't understand yet OpenSolaris only does that with
SPARC64 CPUs. On the other hand I think that also addressing the user TSB
physically and thus avoiding nested traps would get us closer to sharing
this code with sun4v, which only supports trap level 0 and 1, so eventually
we could have a single kernel which runs on both sun4u and sun4v (as does
Linux and OpenBSD).
Developed at and committed from: 27C3
STICK/STICK_COMPARE independently of the selected instruction set by
TICK_COMPARE so tick.c as of r214358 once again can be compiled with
gcc -mcpu=v9 for reference purposes.
kernel address space in order to leave space for the buffer cache, pipes,
thread stacks, etc on machines with more physical memory until we take
advantage of ASI_ATOMIC_QUAD_LDD_PHYS on CPUs providing it so we don't need
to lock the kernel TSB pages into the dTLB, basically making the entire
64-bit kernel address space available on relevant machines.
Submitted by: alc
Passing a count of zero on i386 and amd64 for [I386|AMD64]_BUS_SPACE_MEM
causes a crash/hang since the 'loop' instruction decrements the counter
before checking if it's zero.
PR: kern/80980
Discussed with: jhb
DEBUG_MEMGUARD panics early in kmeminit() with the message
"kmem_suballoc: bad status return of 1" because of zero "size" argument
passed to kmem_suballoc() due to "vm_kmem_size_max" being zero.
The problem also exists on ia64.
creation of large page mappings in the pmap, it can provide modest
performance benefits. In particular, for a "buildworld" on a 2x 1GHz
Ultrasparc IIIi it reduced the wall clock time by 2.2% and the system
time by 12.6%.
Tested by: marius@
contents of the ones that were not empty were stale and unused.
- Now that <machine/mutex.h> no longer exists, there is no need to allow it
to override various helper macros in <sys/mutex.h>.
- Rename various helper macros for low-level operations on mutexes to live
in the _mtx_* or __mtx_* namespaces. While here, change the names to more
closely match the real API functions they are backing.
- Drop support for including <sys/mutex.h> in assembly source files.
Suggested by: bde (1, 2)
work properly with single-stepping in a kernel debugger. Specifically,
these routines have always disabled interrupts before increasing the nesting
count and restored the prior state of interrupts after decreasing the nesting
count to avoid problems with a nested interrupt not disabling interrupts
when acquiring a spin lock. However, trap interrupts for single-stepping
can still occur even when interrupts are disabled. Now the saved state of
interrupts is not saved in the thread until after interrupts have been
disabled and the nesting count has been increased. Similarly, the saved
state from the thread cannot be read once the nesting count has been
decreased to zero. To fix this, use temporary variables to store interrupt
state and shuffle it between the thread's MD area and the appropriate
registers.
In cooperation with: bde
MFC after: 1 month
need locking as otherwise we may race against the other parts of the
MD code which expects a consistent state of these. While at it move
the resetting of the pmap before entering it in the TSB.
- Spell a 0 as TLB_CTX_KERNEL.
introduce function pointers once set up to the respective implementation
for reading the (S)TICK and writing the (S)STICK_COMPARE registers as a
compromise between duplicating code and selecting between different
implementations during execution over and over again, similar to what is
done elsewhere in the MD in order to support different CPU models that
won't ever change at runtime.
- In the remaining tick interrupt handler further push down disabling of
interrupts to the periodic case as it isn't necessary here in one-shot
mode at all.
a critical section as apparently required by both. I don't think either
belongs in the event timer front-ends but the callback should handle
this as necessary instead just like for example intr_event_handle()
does but this is how the other architectures currently handle it, either
explicitly or implicitly.
- Further rename and reword references to hardclock as this front-end no
longer has a notion of actually calling it.
drift in order to achieve a more stable clock as the tick intervals may
vary in the first place. In fact I haven't seen this code kick in when
in oneshot-mode so just skip it in that case.
- There's no need to explicitly stop the (S)TICK counter in oneshot-mode
with every tick as it just won't trigger again with the (S)TICK compare
register set to a value in the past (with a wrap-around once every ~195
years of uptime at 1.5 GHz this isn't something we have to worry about
in practice).
- Given that we'll disable interrupts completely anyway there's no
need to enter critical sections.
what is done on other platforms. Unlike as with the sched_throw(NULL)
called on BSPs during their startup apparently there's nothing which will
reliably lower it on APs. I'm unsure why this only came up on V215 though,
breaking these with r207248. My best guess is that these are the only
supported ones so far fast enough to loose some race.
PR: 151404
MFC after: 3 days
to the expected type so they work like the corresponding __bswapN_var()
functions and the compiler doesn't complain when arguments of different
width are passed.
The check for alignment should be made against the physical address and not
the virtual address that maps it.
Sponsored by: NetApp
Submitted by: Will McGovern (will at netapp dot com)
Reviewed by: mjacob, jhb
the location, apply elf_relocaddr to the symbol value to have right
values for the symbols from dpcpu segment.
PR: kern/147769
Discussed with: avg
Tested by: marius
MFC after: 2 weeks
additionally takes advantage of the prefetch cache of these CPUs.
Unlike the uncommitted US-III version, which provide no measurable
speedup or even resulted in a slight slowdown on certain CPUs models
compared to using the US-I version with these, the SPARC64 version
actually results in a slight improvement.
