Messages in this thread | | | Date | Thu, 9 Jun 2022 14:27:11 +0200 | From | "Jason A. Donenfeld" <> | Subject | Re: [PATCH printk v5 1/1] printk: extend console_lock for per-console locking |
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Hi Dmitry,
On Thu, Jun 09, 2022 at 02:18:19PM +0200, Dmitry Vyukov wrote: > > AFAIK, CONFIG_PROVE_RAW_LOCK_NESTING is useful for teasing out cases > > where RT's raw spinlocks will nest wrong with RT's sleeping spinlocks. > > But nobody who wants an RT kernel will be using KFENCE. So this seems > > like a non-issue? Maybe just add a `depends on !KFENCE` to > > PROVE_RAW_LOCK_NESTING? > > Don't know if there are other good solutions (of similar simplicity).
Fortunately, I found one that solves things without needing to compromise on anything: https://lore.kernel.org/lkml/20220609121709.12939-1-Jason@zx2c4.com/
> Btw, should this new CONFIG_PROVE_RAW_LOCK_NESTING be generally > enabled on testing systems? We don't have it enabled on syzbot.
Last time I spoke with RT people about this, the goal was eventually to *always* enable it when lock proving is enabled, but there are too many bugs and cases now to do that, so it's an opt-in. I might be misremembering, though, so CC'ing Sebastian in case he wants to chime in.
Jason
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