Le 16/05/12 10:45, Christoph Egger a écrit :
On 05/13/12 13:24, Martin Husemann wrote:On Sun, May 13, 2012 at 01:04:15PM +0200, Jean-Yves Migeon wrote:Are you sure that moving to low priority xcalls is the way to go? You can end up with CPUs not being updated because they are offline.Curiously, while I could reproduce the crash before this commit, I am unable to reproduce it in any testing without the actual ucode update happening - and I can not spot a bug in the xcall code that tries to make sure the number of cpus that did run the callback is == the expected count before returning. This clearly needs full analyzis.I am pleased to revert this change once this xcall(9) issue has been fixed.
Sure, however I can't see where the xcall(9) code goes wrong. Care to give more details, please? I cannot reproduce it on my side.
I am using xcall(9) to flush CPU-bound pool caches and having this sort of bug can definitely cause serious cache incoherency that are hard to track down afterwards.
Is it specific to high priority xcalls? -- Jean-Yves Migeon jeanyves.migeon%free.fr@localhost