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A comment on Waiting for Postgres 18: Accelerating Disk Reads with Asynchronous I/O. Parent comment

Re:Waiting for Postgres 18: Accelerating Disk Reads with Asy... by the8472 on Thursday May 08, 2025 @05:24AM (#43924509)
On the kernel side there's a boot parameter for all of them: mitigations=off Software that was compiled with additional fences may have to be recompiled to remove them.

https://www.kernel.org/doc/html/latest/admin-guide/kernel-pa...

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Re:Waiting for Postgres 18: Accelerating Disk Reads with Asy... by starspangled on Thursday May 08, 2025 @10:02AM (#43926182)
mitigations=off disables workarounds for bugs or "mis-features" in the CPU that could be exploited to bypass OS security measures.

smap is an OS security measure, and so does not get disabled by mitigations=off. smap can be pretty draining for certain IO performance though. IMO it should be more well-known or covered by a more obvious option.

Linux kernel developers are really bad at defining and naming options like this.

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