[PATCH v8 0/7] Optimize dm-verity and fsverity using multibuffer hashing

[Herbert Xu]

On Sat, Feb 15, 2025 at 07:26:16PM -0800, Eric Biggers wrote:
>
> Well, the async fallback (using cryptd) occurs only when a kernel-mode FPU
> section in process context is interrupted by a hardirq and at the end of it a
> softirq also tries to use kernel-mode FPU.  It's generally a rare case but also
> a terrible implementation that is really bad for performance; this should never

It may not be rare if the kernel is busy doing bidirectional
TX/RX with crypto.  The process context will be the TX-side
encrypting while the softirq context will do RX-side decryption.

> have been implemented this way.  I am planning to fix it so that softirqs on x86

Sure but it's way better than falling back to the C implementation
on the RX-side.

> will always be able to use the FPU, like they can on some of the other arches
> like arm64 and riscv.

That's great news.  Thanks!
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
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