Lectem

6 ms·

1.
by Lectem 8mo ago
>You say this with zero data. Or so you assume > Spinning by pausing or doing anything else results in worse performance. We measured this countless times. And I've seen the issue in hundreds of captures using a profiler. I suppo
2.
by Lectem 8mo ago
I mean my "No it isn't, it has a fixed number of yields, which has a very different duration on various CPUs" can be verified directly by having a look at the table in my article showing different timings for pause. For the y
3.
by Lectem 8mo ago
I suppose you need to be able to read data from the buffers to know what parts of the graph to cull? Is computing the graph really long or the graph needs update mid execution? If you really have nothing else to do on those threads/cor
4.
by Lectem 8mo ago
That's a spin loop ;)
5.
by Lectem 8mo ago
That's how they are supposed to work indeed! But spin locks aren't the only spin loops you may find, and allocator for example do spin. And for example under an allocation heavy code (that you should avoid too, but happens due to
6.
by Lectem 8mo ago
The issue with that is that a load fence may be very detrimental to perf. It doesn't really matter if rdtsc executes out of order in this code anyway, and there is no need for sync between cores.
7.
by Lectem 8mo ago
I've heard of issues on Arm devices with properly isolated cores (only one thread allowed, interrupts disabled) because the would interact with other threads using such a spinlock, threads which were not themselves isolated. The team r
8.
by Lectem 8mo ago
> which themselves do a short userspace spin-wait and then fall back to a kernel wait queue on contention. Yes, but sadly not all implementations... The point remains that you should prefer OS primitives when you can, profile first, red
9.
by Lectem 8mo ago
The author (me) actually read this long ago > - It as an optimal amount of spinning No it isn't, it has a fixed number of yields, which has a very different duration on various CPUs > Threads wait (instead of spinning) if the loc
10.
BadAccessGuards- C++ library to detect raceconditions faster than TSan(github.com)
2 points by Lectem 2y ago|0 comments
11.
by Lectem 7y ago
Yeah... why share something that is 2 years old ?
12.
by Lectem 8y ago
Looks like ArtStation didn't bribe Google like the rest of the big apps like Instagram, Facebook, Twitter... I'm surprised people forget that Google now IS evil and corrupt, and are just squashing "small" companies in fa
13.
by Lectem 8y ago
I wouldnt trust google with anything anymore. Their customer support (entreprise or not) always sucked. They're always "right". You can only suffer the damage silently unless you're worth millions for them. People should