Currently it is not possible to check if a message was sent over a bus
or if it was send the usual way using `msg_send()`.
This adds a flag to the `sender_pid` if the message was sent over a bus.
`MAXTHREADS` is currently set to 32, so there is still plenty of room in
the PID space. (`kernel_pid_t` is `int16_t`)
The message type for bus message type is already accessed through a getter
function, so it's just consistent to do the same for sender_pid.
Verified that each warning generated by -Wcast-align is indeed a false positive
and used an (intermediate) cast to `uintptr_t` to silence the warnings.
container_of() is safe to use in regard to alignment requirements, when used
correctly. Using `uintptr_t` instead of `char *` for applying the offset results
in -Wcast-align not complaining.
Separate thread names from DEVELHELP so thread names can be
enabled in non-development/debug builds when required/desired.
THREAD_NAMES will be enabled by default then DEVELHELP is set to 1.
Allocate and initialize a thread-local block for each thread at the
top of the stack.
Set the tls base when switching to a new thread.
Add tdata/tbss linker instructions to cortex_m and risc-v scripts.
Signed-off-by: Keith Packard <keithp@keithp.com>
---
v2:
Squash fixes
v3:
Replace tabs with spaces
v4:
Add tbss to fe310 linker script
- Add `byteorder_bebuftohll()` to read an 64 bit value from a big endian buffer
- Add `byteorder_htobebufll()` to write an 64 bit value into a big endian buffer
This commit reverses the runqueue_cache bit order when the architecture
has a CLZ (count leading zeros) instruction. When the architecture
supports CLZ, it is faster to determine the most significant set bit of
a word than to determine the least significant bit set. Unfortunately
when the instruction is not available, it is more efficient to determine
the least significant bit set.
Reversing the bit order shaves off another 4 cycles on the same54-xpro.
From 147 to 143 ticks when testing with tests/bench_sched_nop.
Architectures where no CLZ instruction is available are not affected.
Apparently clang doesn't like static variables / functions being accessed called
from inline function (-Wstatic-in-inline). This commit results in the same
binary being generated while making clang happy.
Replace accesses to `sched_active_thread`, `sched_active_pid`, and
`sched_threads` with `thread_get_active()`, `thread_get_active_pid()`, and
`thread_get_unchecked()` where sensible.
- Add `thread_get_active()` to access the TCB
- Add `thread_get_unchecked()` as fast alternative to `thread_get()`
- Drop `volatile` qualifier in `thread_get()`
- Right now every caller of this function does this. It is better to
contain this undefined behavior to at least one place in code
The `clz` instruction pretty much implements getting the most significant bit
in hardware, so use it instead of the software implementation.
This reults in both a reduction in code size as in a speedup:
master:
text data bss dec hex filename
14816 136 2424 17376 43e0 tests/bitarithm_timings/bin/same54-xpro/tests_bitarithm_timings.elf
+ bitarithm_msb: 3529411 iterations per second
this patch:
text data bss dec hex filename
14768 136 2424 17328 43b0 tests/bitarithm_timings/bin/same54-xpro/tests_bitarithm_timings.elf
+ bitarithm_msb: 9230761 iterations per second
Big endian buffers on big endian systems are already in big endian byte order,
so no byte shuffling is needed. However, byte buffers might be unaligned, so
copy operations that are safe with unaligned memory accesses need to be
used.
