they reduce the average length per encoded value compared to fixed-width encoding, if the encoded values are from a large range, but the most common values are generally small (and hence are using only a small fraction of that range most of the time).
一般的 Time Sync Service 服務大多是 ms 等級，也就是 10-3 秒這個等級，μs 則是到了 10-6...
但這其實有點詭異，目前只有 AWS 東京區有這個服務，而且限制在 r7g 的機器上才能用：
Amazon Time Sync with microsecond-accurate time is available starting today in the Asia Pacific (Tokyo) Region on all R7g instances, and we will be expanding support to additional AWS Regions and EC2 Instance types.
也就是說 us-east-1、us-west-2 這些第一線熱門的區域沒有，另外只有特別的 ARM 機種，而且是 memory-intensive 的 r7g 才能用？
Starting October 31, 2023, you will have the option to opt in individual Workers and Pages Functions projects on your account to new pricing, and newly created projects will default to new pricing. You’ll be able to estimate how much new pricing will cost in the Cloudflare dashboard. For the majority of current applications, new pricing is the same or less expensive than the previous Bundled and Unbound pricing plans.
另外明年 2024/03/01 會全部強制切到新的方案：
If you’re on our Workers Paid plan, you will have until March 1, 2024 to switch to the new pricing on your own, after which all of your projects will be automatically migrated to new pricing. If you’re an Enterprise customer, any contract renewals after March 1, 2024, will use the new pricing.
作者發現是因為 find() 找出所有的連結後 (a 元素)，跑去每一個連結上面綁定事件造成的效能問題：
The .on("click") call attached a click event listener to nearly every link in the content so that the corresponding section would open if the clicked link contained a hash fragment. For short articles with few links, the performance impact was negligible. But long articles like ”United States” included over 4,000 links, leading to over 200ms of execution time on low-end devices.
Worse yet, this behavior was unnecessary. The downstream code that listened to the hashchange event already called the same method that the click event listener called. Unless the window’s location already pointed at the link’s destination, clicking a link called the checkHash method twice — once for the link click event handler and once more for the hashchange handler.
This was accomplished by changing the file format so we can mmap() weights directly into memory without having to read() or copy them thereby ensuring the kernel can make its file cache pages directly accessible to our inference processes; and secondly, that the file cache pages are much less likely to get evicted (which would force loads to hit disk) because they're no longer competing with memory pages that were needlessly created by gigabytes of standard i/o.
另外 Justine Tunney 在這邊的 comment 有提到一個意外觀察到的現象，他發現實際在計算的時候用到的 model 內容意外的少：他用一個簡單的 prompt 測試，發現 20GB 的 30B model 檔案在他的 Intel 機器上實際只用到了 1.6GB 左右：
If I run 30B on my Intel machine:
[...]
As we can see, 400k page faults happen, which means only 1.6 gigabytes ((411522 * 4096) / (1024 * 1024)) of the 20 gigabyte weights file actually needed to be used.
這點他還在懷疑是不是他的修改有 bug，但目前他覺得不太像，也看不太出來：
Now, since my change is so new, it's possible my theory is wrong and this is just a bug. I don't actually understand the inner workings of LLaMA 30B well enough to know why it's sparse. Maybe we made some kind of rare mistake where llama.cpp is somehow evaluating 30B as though it were the 7B model. Anything's possible, however I don't think it's likely. I was pretty careful in writing this change, to compare the deterministic output of the LLaMA model, before and after the Git commit occurred. I haven't however actually found the time to reconcile the output of LLaMA C++ with something like PyTorch. It'd be great if someone could help with that, and possibly help us know why, from more a data science (rather than systems engineering perspective) why 30B is sparse.
Focus on what's mission-critical: Removal of free dynos, hobby-dev Heroku Postgres and hobby-dev Heroku Data for Redis plans starting November 28, 2022 and inactive account deletion starting October 26, 2022.
取而代之的是針對特定團體條件性的開放，分成三類：學生、非營利組織以及 open source 專案。但前兩個目前方案都還沒出來，要晚點才會公佈；後面的 open source 專案則是要寄信申請。
In the context of file system TOCTOU race conditions, the fundamental challenge is ensuring that the file system cannot be changed between two system calls. In 2004, an impossibility result was published, showing that there was no portable, deterministic technique for avoiding TOCTOU race conditions.
其中一種 mitigation 是針對 fd 監控：
Since this impossibility result, libraries for tracking file descriptors and ensuring correctness have been proposed by researchers.
然後另外一種方式 (比較治本) 是檔案系統的 API 支援 transaction，但看起來不被主流接受？
An alternative solution proposed in the research community is for UNIX systems to adopt transactions in the file system or the OS kernel. Transactions provide a concurrency control abstraction for the OS, and can be used to prevent TOCTOU races. While no production UNIX kernel has yet adopted transactions, proof-of-concept research prototypes have been developed for Linux, including the Valor file system and the TxOS kernel. Microsoft Windows has added transactions to its NTFS file system, but Microsoft discourages their use, and has indicated that they may be removed in a future version of Windows.
時，會需要 
bit 表達，像是 
時，會需要 3 個 bit 表達，從 
輸入，拿 
與餘數 
：
