dfox

44 ms·

511.
by dfox 5y ago
RET is typically special cased in the speculation logic. I suspect that this construction will have significantly larger miss prediction rate (on some uArchs quite possibly 100%) than straight indirect jump.
512.
by dfox 5y ago
The better takeaway is that on ELF/PIC platforms a call to dynamically linked function is somewhat more expensive than one would assume. With modern CPU architectures that can prefetch/speculate over indirect jump/call making
513.
by dfox 5y ago
Mozilla Suite also had toolbar for this kind of links. And early versions of Firefox either had it too or there was extension for it.
514.
by dfox 5y ago
Massively parallel was just an marketing buzzword that was used for a lot of different things. One thing to look for is wether all the compute elements run from same clock or not. CM1/2 is SIMD machine that is mostly nothing more than
515.
by dfox 5y ago
This is also true for X.509, there is exactly zero reason to generate new key (if it was not compromised) or even new CSR for certificate renewal. Yet people tend to do this which only increases the opportunities to fuck something up in the
516.
by dfox 5y ago
The common way of managing ssh keys involves having some central entity that somehow updates the authorized_keys on all relevant hosts, which involves interaction with all the hosts which is somehow triggered by interaction with the user re
517.
by dfox 5y ago
It is combination of two things. X.509 is arguably overly complex ASN.1/X.500 thing, but that is not the main issue. Main issue is that most people do not even grasp the concept of a certificate (ie. binding of public key to some addit
518.
by dfox 5y ago
For win32 style code multiple different versions of msvcrt in same process is mostly fine except when some of the dlls involved in that is built without sxs manifest (it will probably still work, but produces modal ShowMessage saying that y
519.
by dfox 5y ago
The right assumption is that every syscall can return any defined errno value. In practice this means that you should handle the cases that you have to handle (-EINTR and for write(2) incomplete writes, which are typical reason for “fatal e
520.
by dfox 5y ago
Userspace should not expect that any given syscall can only return some set of known errno values. You should enumerate the cases where you want to do some kind of special handling (with EINTR being somewhat more important that other cases)
521.
by dfox 5y ago
One thing to keep in mind while programming AVR in C is that it still is small-ish MCU with different address spaces. This means that if you do not use correct compiler-specific type annotations for read-only data these will get copied into
522.
by dfox 5y ago
I2C is one thing, Dallas datasheets that completely document the relevant subset of the 1wire state machine are another beast… On the other hand in the last month I have seen 40 page datasheets from Phillips/NXP/Nexperia that cont
523.
by dfox 5y ago
There is. Last christmas I had the idea to buy iPhones for my parents, side effect of that was finding out that there is 1000+ page manual for every iOS/iPadOS release which is localized for every country where the relevant thing is so
524.
by dfox 5y ago
It uses mid-power LED originally intented for automotive brake lights (when it was designed the LED used probably was considered "high-power").
525.
by dfox 5y ago
The main issue with fexprs is that while it is neat way to generalize straightforward interpreter it makes implementation of compiler (or in fact almost anything requiring code walking, including some more advanced macros) unnecessarily com
526.
by dfox 5y ago
It is my understanding that for "sane" charger topologies (ie. without tricks that share power components between charger and drivetrain) of the power level required for EV charger the SMPS comes out capable of bidirectional opera
527.
by dfox 5y ago
4 workers is the sweet spot for most wsgi applications. Typically you will scale above that by running additional complete gunicorn instances (managed by some kind of external scaling/load balancing thing). If it makes sense for your a
528.
by dfox 5y ago
I suspect that the giant switch was exactly the reason why it was not originally possible.
529.
by dfox 5y ago
PostgreSQL used to have two different APIs for internal/C language SQL functions, with the older one implemented in more or less this manner, but with distinct types for each argument count. The actual function call was then implemente
530.
by dfox 5y ago
ECC is not inherently slower. Registered modules are slower (by the added latency of the register). ECC-or-not and registered-or-not are two orthogonal features of the DIMM and in theory all four combinations are possible. On the other hand
531.
by dfox 5y ago
As I read it I think that the idea there is to allow usage of pattern where the resulting resource refers to other resources that somehow encode the contents of the QUERY request body in their URL (or even results in redirect to such resour
532.
by dfox 5y ago
My understanding is that the original vacuum tube based IBM computers on which Lisp was implemented were accumulator based architectures (ie. had one register usually named "accumulator") with some instructions using parts of the
533.
by dfox 5y ago
I would hazard a guess that most used "software module of any description" is dtoa().
534.
by dfox 5y ago
The no flags at all part is clearly inspired by Alpha including the rationale of flags being detrimental to OoO implementation. MIPS is classical RISC design that was not designed to be OoO-friendly at all and is simply designed for ease of
535.
by dfox 5y ago
Essentially all DOS graphical extensions used DOS for filesystem implementation, including GEOS, and more notably Windows before the 3.1 (3.1 had user option in control panel to use Windows-native FAT implementation) and 9x (which could use
536.
by dfox 5y ago
There are some Microchip chips that implement weird SPI/I2C hybrid which does I2C-like slave addressing over SPI. But thats it for the addressing.
537.
by dfox 5y ago
which implies that the power state of the whole core cluster is on, so the syscall is defined to return 1
538.
by dfox 5y ago
In the Windows 9x days this was quite common and there were linux distributions that were installed by unzipping few hundred MB zipfile into C:\linux\. It only worked with FAT filesystem and the required umsdos FS module was removed from ke
539.
by dfox 5y ago
Direct ancestor probably is mask-and-tape PCB design process, where the optical step also serve to shrink the (hand made) mask to significantly smaller size of the final board. In fact silicon masks were for a long time designed using essen
540.
by dfox 5y ago
The issue there is that the hardware is full of totally absurd bugs. If you target PC-like userspace or one of the two major mobile platforms it is somebody else's job to shield you from that. In general CPU level bugs are somewhat rar

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