Friday, 2021-05-14

lkclrush-job, for lauri to be able to do mp3 decode, i'm adding FP support to the ISACaller simulator17:44
lkcli'm going to need help, esp. with unit tests17:55
programmerjakejust finished the WebAssembly SIMD meeting, they were quite interested in SimpleV18:05
lkclthat's a good sign.18:15
programmerjakelink to meeting minutes:
programmerjakewhat's written is an approximation of what we said...18:21
programmerjakebetter link:
lkclFL: what happens when you reduce VL to data that is out of bounds in registers18:39
lkclhis question's slightly unclear18:39
lkclif it was this:18:39
programmerjakeI think he meant: how do you prevent it from messing up registers past what the compiler allocated18:40
lkclright. yeah18:41
programmerjakethe minutes are a loose approximation of what was said18:41
lkclthen it's the compiler's job to know the allocation18:41
lkclby way of issuing a setvl with a "maxvl=NN" argument18:41
programmerjakeyup, I think I adequately explained that to him18:41
lkcl(which is always static - no way to set it dynamically from a register, this is very deliberate)18:42
lkcland setvl *never* exceeds the current maxvl18:42
lkcl"If you run the configure vector instruction, it throws away all the stuff."18:42
lkclwe *do not* do that18:42
lkclbecause it's on top of the standard regfiles18:43
programmerjakethat's risc-v v's reconfigure vectors instruction18:43
lkclbecause they literally reconfigure the entire engine, internally18:43
lkcli think there may be an option now to sit on top of the FP regfile18:44
lkclbtw well done not freaking them out with the different modes or with twin predication at an early stage :)19:04
lkcli worked out a way to say what twin predication is: "back-to-back VREDUCE-VEXPAND, for any single-src single-dest arithmetic or memory operation"19:05
lkclor better just "for any single-src single-dest operation"19:05
programmerjakeI tried to reduce it to the features that require a fundamental rethink at the compiler-level, the rest of the stuff I'd consider more to be just new operations19:26
programmerjakemy home file server won't boot after an automatic upgrade...will have to figure out what broke... fun!19:29
lkclngggh, now you know why i disable automatic updates...19:50
lkclgaah found a long-standing bug that shouldn't have been in ISACaller (and wasn't for a long time)21:30
programmerjakeit appears as though my HDDs are taking too long to come online, so the mount service is timing out, causing the system to go into emergency mode without a running ssh server...had to move it all to another room where I have a screen and keyboard21:47
lkcladd "bootdelay=something" in seconds to /etc/default/grub21:54
lkclsorry, "rootdelay=NNN"21:55
programmerjakemy root drive is a usb flash drive -- no issues there22:08
programmerjakeI'm trying adding x-systemd.device-timeout=300s to fstab22:09
programmerjakeit works!22:10
lkclinteresting choice of root boot media :)22:19
lkcli mount /tmp, /var/tmp, and many other locations onto tmpfs when using usb flash22:19
lkclotherwise you end up with massive wear on something that wasn't designed for it, and goodbye server22:20
programmerjakeno tmpfs for me ... odroid xu4 with only 2GB ram22:28
programmerjakeI'm using the flash drive because it's *waay* better than the sdcard it's designed to use, the sdcard would wear out in a year22:29
programmerjakeI changed it to only have /boot on the sdcard22:30
programmerjakeit's a 128GB flash drive, so it's less likely to quickly wear out from the few MB of temp files22:31
programmerjakebesides...when it does finally wear out, that'll motivate me to finally get around to upgrade from ubuntu 16.0422:33
choozyprogrammerjake, does it help to use f2fs? Or something like that?22:34
programmerjakeidk, i'm using ext422:34

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