Linux KPTI Tests Using Linux 4.14 vs. 4.9 vs. 4.4

[Michael]

Does enabling KPTI print something to dmesg or is there some other way to check that? I didn't notice anything on my Haswell laptop running 4.14.11-1-ARCH, but I'd like to verify that its enabled (or disabled with nopti option, if I try it).

As mentioned in the article and shown in the screenshots, the very latest patches do.

[Tomin]

Does enabling KPTI print something to dmesg or is there some other way to check that? I didn't notice anything on my Haswell laptop running 4.14.11-1-ARCH, but I'd like to verify that its enabled (or disabled with nopti option, if I try it).

[dungeon]

Michael, there are a lot of Google's services at spectre of risks , so even net might start to missbehave in various weird ways at least temporarely these days

https://support.google.com/faqs/answer/7622138

[Michael]

The results on page 2 are totally broken on Chrome. Each result is a separate frame with a vertical and horizontal scroll bar, showing a quarter of the result.
Shows fine in firefox.

Do you have the new site isolation feature enabled? Have heard it's breaking the graph rendering but haven't had time to investigate yet.

[elapsed]

The results on page 2 are totally broken on Chrome. Each result is a separate frame with a vertical and horizontal scroll bar, showing a quarter of the result.
Shows fine in firefox.

[rubdos]

As far as I understand, KPTI should have a larger impact when doing kernel <-> userland context switches, which explains why Apache and Redis are hit (they need networking), but others are not.

[Michael]

Michael do you still have in your possession those Tyan servers with with the Intel Xeons? Since the patches effect certain workloads that are more relevant to servers it'd be great to see some benchmarks

I've already been posting benchmarks from them the other day.

[puleglot]

There will be CPU microcode updates from Intel and AMD for Spectres... i think people and Michael should wait all thing to be there and retest performance then

Yeah. And disabling branch prediction will likely affect gaming performance.

[dungeon]

There will be CPU microcode updates from Intel and AMD for Spectres... i think people and Michael should wait all thing to be there and retest performance then

Meanwhile i will joke_patching fglrx to make me gpu_insecure also

So.

Much ado about nothing.

Really? Up to 35% lower performance on the latest kernel is nothing for you?