On Wed, Mar 24, 2010 at 12:57:46AM -0400, Oren Laadan wrote: > On Tue, 23 Mar 2010, Matt Helsley wrote: > > > On Tue, Mar 23, 2010 at 08:53:42PM +0000, Russell King - ARM Linux wrote: > > > On Sun, Mar 21, 2010 at 09:06:03PM -0400, Christoffer Dall wrote: > > > > This small commit introduces a global state of system calls for ARM > > > > making it possible for a debugger or checkpointing to gain information > > > > about another process' state with respect to system calls. > > > > > > I don't particularly like the idea that we always store the syscall > > > number to memory for every system call, whether the stored version is > > > used or not. > > > > > > Since ARM caches are generally not write allocate, this means mostly > > > write-only variables can have a higher than expected expense. > > > > > > Is there not some thread flag which can be checked to see if we need to > > > store the syscall number? > > > > Perhaps before we freeze the task we can save the syscall number on ARM. > > The patches suggest that the signal delivery path -- which the freezer > > utilizes -- has the syscall number already. > > > > Should work since the threads must be frozen first anyway. > > I like the idea. > > However, would it also work for those cases when the freezing does not > occur from the signal delivery path - e.g. for vfork and ptraced tasks ? We could just as easily set it before the vfork uninterruptible completion. ptracing I'd don't know about though. Cheers, -Matt Helsley _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
