On Mon, 13 Sep 2010 21:49:20 +0200 Peter Zijlstra <pet...@infradead.org> wrote:
> On Mon, 2010-09-13 at 21:35 +0200, Andi Kleen wrote: > > Stephane Eranian <eran...@google.com> writes: > > > > > The DS, BTS, and PEBS memory regions were allocated using > > > kzalloc(), i.e., requesting contiguous physical memory. There is > > > no such restriction on DS, PEBS and BTS buffers. Using kzalloc() > > > could lead to error in case no contiguous physical memory is > > > available. BTS is requesting 64KB, thus it can cause issues. PEBS > > > is currently only requesting one page. Both PEBS and BTS are > > > static buffers allocated for each CPU at the first user. When the > > > last user exists, the buffers are released. > > > > DS supports page tables, but I have some doubts it really > > supports page faults. vmalloc today does page faults. > > > > I think the change is a good idea, but it will need > > vmalloc_sync_all() everywhere. > > Right, I seem to remember from that last discussion on vmalloc vs NMI > that vmalloc_sync_all() had some issues, or am I totally > mis-remembering that? Linus thought it was ugly, but he never explained why and it was not obvious to me. His proposed replacement wouldn't work for this case. I am not aware of any real technical issues, except that it needs to be done for both 32bit and 64bit. -Andi -- a...@linux.intel.com -- Speaking for myself only. ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
