* Rusty Russell (rusty@rustcorp.com.au) wrote:I wouldn't mind if it was limited to the code within do_nmi(), but then we would have to accept potential GPF if A - the NMI or MCE code calls any external kernel code (printk, notify_die, spin_lock/unlock, die_nmi, lapic_wd_event (perfctr code, calls printk too for debugging)... B - we try to patch this code at the wrong moment I could live with that, but I would prefer to have a solid, non flaky solution. My goal is to help the kernel quality _improve_ rather than deteriorate. Therefore, if one decides to use the immediate values to leave dormant spinlock instrumentation in the kernel, I wouldn't want it to have undesirable side-effects (GPF) when the instrumentation is being enabled, as rare as it could be. If we choose to go this way, stop_machine would have to do a sync_core() on every CPU before it reactivates interrupts for this to respect Intel's errata. It's not just a matter of not executing the code while it is modified; the issue here is that we must insure that we don't have an incoherent trace cache. So, as is, stop_machine would not respect the errata. Mathieu -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -
| Justin C. Sherrill | Re: dragonflybsd.org website link? |
| David Woodhouse | Re: -mm merge plans for 2.6.23 |
| Greg Kroah-Hartman | [PATCH 002/196] Chinese: rephrase English introduction in HOWTO |
| Eric Sandeen | Re: [RFC] Heads up on sys_fallocate() |
git: | |
| David Miller | [GIT]: Networking |
| Gerrit Renker | [PATCH 15/37] dccp: Set per-connection CCIDs via socket options |
| Patrick McHardy | [NET_SCHED 01/15]: sch_atm: fix format string warning |
