kdave
kdaveInteresting. The highly optimized unrolled implementation of CRC32C on intel is about the same speed as a tight loop around ‘crc32q’. Both do like 30G/s on a 4KiB block with many iterations. Also compared to an older code of the tight loop with one extra instruction (probably causing register dependency with crc32q) is about 11G/s instead.
45d350: ┌─> 48 8b 08 movq (%rax),%rcx
45d353: │ f2 48 0f 38 f1 f1 crc32q %rcx┌%rsi
45d359: │ 48 83 c0 08 addq $0x8┌%rax
45d35d: │ 48 39 d0 cmpq %rdx┌%rax
45d360: └── 75 ee jne 45d350 <crc32c_sse42+0x30>vs:
455000: ┌─> 48 8b 08 movq (%rax),%rcx
455003: │ 89 fe movl %edi┌%esi
455005: │ f2 48 0f 38 f1 f1 crc32q %rcx┌%rsi
45500b: │ 89 f7 movl %esi┌%edi
45500d: │ 48 83 c0 08 addq $0x8┌%rax
455011: │ 48 39 d0 cmpq %rdx┌%rax
455014: └── 75 ea jne 455000 <crc32c_intel+0x20>The optimized linux starts at https://elixir.bootlin.com/linux/latest/source/lib/crc/x86/crc-pclmul-template.S . This also has the AVX versions that could be faster than plain ‘crc32’ instruction.
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@lkundrak https://cs.wikipedia.org/wiki/St%C5%99ezim%C3%AD%C5%99 This village exists just to prove you wrong.
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kdave
kdave
_The_ 3com Etherlink III 3c509 driver is being removed (https://lwn.net/ml/all/20260421-v7-0-0-net-next-driver-removal-v1-v1-1-69517c689d1f@lunn.ch/)
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kdave
kdave
https://github.com/OpenKernel-edu/emoji-kernel-edu Assembly in emojis. 📥 42 🖨️ ⏹️ is "Print 42 and exit".
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kdave
kdave
What a random bug. On a new testing instance, with enough VM memory, somehow working kernel config. On the first run a memory allocation failure that would not otherwise happen 2s after boot, but now it identified "delayed error handling" that allowed a NULL pointer dereference. With a fix it did not hit any allocation errors at all.
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kdave
repeated
repeated
Vlastimil Babka 🇨🇿🇪🇺🇺🇦
vbabka@mastodon.social
Edited 3 months ago
Once again there's a kernel developer position open in the SUSE Labs Kernel Core team I'm part of! https://suse.wd3.myworkdayjobs.com/en-US/Jobsatsuse/job/Czech-Republic-EMEA/Linux-Kernel-Generalist_71007379
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@ptesarik @oleksandr I also meant the forks of firefox or the ground up new browsers, but it's too fragmented and unusable indeed.
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@ptesarik @oleksandr What do you mean no alternatives? There are at least 17 other browsers to choose from!
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kdave
kdave
https://git.kernel.org/linus/006568ab4c5ca2309ceb36fa553e390b4aa9c0c7 Adding Link: tag to the original discussion is ok but it should not be instead of a proper changelog, namely when there's discussion what exactly is the fix actually doing. Also it's for out of tree module. And it got a CVE.
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@ffmancera You should not skip 42 for reasons that only Univese can understand.
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kdave
kdave
Have some fun, take C keyword quiz https://www.jetpunk.com/user-quizzes/1363547/c-keywords-quiz
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