On 19/01/2026 16:44, Kees Cook wrote:

On January 19, 2026 8:00:00 AM PST, Dave Hansen [off-list ref] wrote:

quoted

On 1/19/26 05:01, Ryan Roberts wrote:

quoted

x86 (AWS Sapphire Rapids):
+-----------------+--------------+-------------+---------------+
| Benchmark       | Result Class |   v6.18-rc5 | per-task-prng |
|                 |              | rndstack-on |               |
|                 |              |             |               |
+=================+==============+=============+===============+
| syscall/getpid  | mean (ns)    |  (R) 13.32% |     (R) 4.60% |
|                 | p99 (ns)     |  (R) 13.38% |    (R) 18.08% |
|                 | p99.9 (ns)   |      16.26% |    (R) 19.38% |

Like you noted, this is surprising. This would be a good thing to make
sure it goes in very early after -rc1 and gets plenty of wide testing.

Right, we are pretty late in the dev cycle (rc6). It would be prudent to get this into -next after the coming rc1 (1 month from now).

On the other hand, the changes are pretty "binary" in the sense that mistakes should be VERY visible right away. Would it be better to take this into -next immediately instead?

I don't think this question was really addressed to me, but I'll give my opinion
anyway; I agree it's pretty binary - it will either work or it will explode.
I've tested on arm64 and x86_64 so I have high confidence that it works. If you
get it into -next ASAP it has 3 weeks to soak before the merge window opens
right? (Linus said he would do an -rc8 this cycle). That feels like enough time
to me. But it's your tree ;-)

Thanks,
Ryan

quoted

But I don't see any problems with the approach, and the move to common
code looks like a big win as well:

Agreed; I think it's looking great.