Messages in this thread | | | Date | Fri, 29 Jun 2012 13:30:12 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 03/23] perf: Add ability to attach user level registers dump to sample |
| |
On Fri, Jun 29, 2012 at 01:23:51PM +0200, Frederic Weisbecker wrote:
SNIP
> > > > well, thats basically what we have now.. > > > > when the kernel is compiled for 32 bits, the bitmask allows to store: > > > > ax, bx, cx, dx, si, di, bp, sp, ip, flags, cs, ds, es, fs, gs, ss > > > > and when kernel is compiled for 64 bits, the bitmask adds 64bit stuff: > > > > ax, bx, cx, dx, si, di, bp, sp, ip, flags, cs, ds, es, fs, gs, ss > > r8, r9, r10, r11, r12, r13, r14, r15 > > > > > > - 32 bits kernel is straightforward > > > > - for 64 bits kernel we store whatever bitmask instructs to, > > regardless if we are in compat task or native 64, > > user space will deal with that in post processing > > I can think of the crazy scenario where perf itself is compat and there > are 64 bits apps that will be profiled by perf. It means perf must check > if the kernel is 32 or 64 and depending on this, request r8-r15 or not. > > May be that's just too unlikely to matter.
hopefully ;) anyway the kernel interface stays the same in this case as well
we can add this check later when/if we deal with compat tasks
jirka
| |