Re: Is Parallel Programming Hard, And, If So, What Can You Do About It?

On 5/20/2025 5:29 PM, Lawrence D'Oliveiro wrote:

On Tue, 20 May 2025 10:49:54 -0400, Stefan Monnier wrote:
 

Indeed, AFAIK, what we call "HDD cache" is actually just the RAM used by
the embedded CPU inside the drive for its operation.

 If it were just I/O buffers for operations in progress, that would be
fine. The problem is when it keeps data around instead of immediately
writing it out, and what’s worse, lies about it, so it tells the OS that
the write has completed when it hasn’t.

So you have no objection to caching data on reads such as reading in subsequent data.  And furthermore, you saw earlier that the host can turn on or off, either for all writes or a particular write, the completion return before the data is on the disk.  No one is "lying". You just have to understand what you are asking for.
--
  - Stephen Fuld
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