On Tue, 6 Feb 2024 at 02:22, Danilo Krummrich <dakr@xxxxxxxxxx> wrote: > > On 1/29/24 02:50, Dave Airlie wrote: > > From: Dave Airlie <airlied@xxxxxxxxxx> > > > > This should break the deadlock between the fctx lock and the irq lock. > > > > This offloads the processing off the work from the irq into a workqueue. > > > > Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> > > Nouveau's scheduler uses a dedicated wq, hence from this perspective it's > safe deferring fence signalling to the kernel global wq. However, I wonder > if we could create deadlocks by building dependency chains into other > drivers / kernel code that, by chance, makes use of the kernel global wq as > well. > > Admittedly, even if, it's gonna be extremely unlikely given that > WQ_MAX_ACTIVE == 512. But maybe it'd be safer to use a dedicated wq. > > Also, do we need to CC stable? I pushed this to Linus at the end of last week, since the hangs in 6.7 take out the complete system and I wanted it in stable. It might be safer to use a dedicated wq, is the concern someone is waiting on a fence in a workqueue somewhere else so we will never signal it? Dave.
