Re: Fedora 34 Change: Scale ZRAM to Full Memory Size (Self-Contained Change proposal)
I apologize for the possible duplicate message, the past didn't show up for reasons I don't understand. I think it's a bad idea. It is better to make `zram-fraction` equal to 0.8 or 0.9, but not 1.0. For example, if you run Darktable, load a floating-point TIFF image into it, and try to export it, on systems with little RAM, it will fill both RAM itself and zram, and cause the system to freeze completely because the memory is almost incompressible. Also, other data (video editors, for example) which are not compressible can get into RAM. ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
Re: Fedora 34 Change: Scale ZRAM to Full Memory Size (Self-Contained Change proposal)
Does this reduce your concern? In a way, yes. Most of the time memory will be compressible, I agree, but there are non-compressible data, and I'm only concerned about that. In my opinion, it's better not to set the zram size to 100% for everyone. Whoever is sure that their data will be compressible can set it to 100%. Are you sure that this data is compressed in memory as well as the on-disk encoding? The editing operations themselves surely operate on uncompressed data, and then it's compressed upon being written to disk. I'm not sure. But I've had a few times where zram didn't compress anything and ended up freezing the system completely. ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
Re: Fedora 34 Change: Scale ZRAM to Full Memory Size (Self-Contained Change proposal)
Is earlyoom disabled on this system? It should send SIGTERM to something in this case - which is not the best UX as a hint that an adjustment needs to be made. But I want to make sure there isn't something else going wrong. Yes, it's off. And I have an assumption that earlyoom may not have time to work if there is a lot of pressure on the memory. ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
Re: Fedora 34 Change: Scale ZRAM to Full Memory Size (Self-Contained Change proposal)
Different question: This sounds like you're handling data that won't fit into RAM+Swap anyway, using zram isn't going to help (or hurt), because with or without compression, your data just doesn't fit in memory. I'm talking about possible outcomes, including the ones I've had. What does the maximum fraction of zram have to do with that? Either way, this sounds like you just don't have enough physical RAM for your workload. In that case, adding physical swap (on disk) is probably the only way to make that work (other than buying more RAM). `zram-fraction = 1`. Yes, I have not enough memory, but even on systems with a large amount of RAM, it is possible what I described earlier. In most cases, of course, with a zram-fraction that equals one (or even more) the system will run stable, but just keep in mind that where data may not be compressed, there may be problems. ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
Re: Fedora 34 Change: Scale ZRAM to Full Memory Size (Self-Contained Change proposal)
It seems I was wrong. I did the same test again, and this time even with more `zram-fraction'. The Darktable memory is compressed, there was no more hang-up problem. Sorry about the noise, maybe it was a regression in the old kernel, or my configuration error somewhere. On 1/12/21 5:55 PM, Matthew Miller wrote: Is this actually incompressible, though? Sure, a compressed TIFF would be, but isn't the raw bitmap loaded into memory likely quite compressible? ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
