On Tue, Feb 18, 2025 at 03:08:46PM -0400, Jason Gunthorpe wrote: > On Tue, Feb 18, 2025 at 11:02:23AM -0800, Nicolin Chen wrote: > > > > > This already holds the streams_mutex across all of this, do you think > > > > > we should get rid of the vmaster_rwsem and hold the streams_mutex on > > > > > write instead? > > > > > > > > They are per master v.s. per smmu. The latter one would make master > > > > commits/attaches exclusive, which feels unnecessary to me, although > > > > it would make the code here slightly cleaner.. > > > > > > I'd pay the cost on the attach side to have a single lock on the fault > > > side.. > > > > OK. Maybe a small patch to turn the streams_mutex to streams_rwsem? > > I don't think the interrupt path is multithreaded, is it? So only 1 > reader anyhow?
Right, it's IRQF_ONESHOT. I will keep that unchanged. Thanks Nicolin
