On Mon, Sep 13, 2010 at 8:42 PM, Peter Zijlstra <pet...@infradead.org> wrote: > On Mon, 2010-09-13 at 20:40 +0200, Stephane Eranian wrote: >> Ok, so can we play the same trick you're playing with the sampling >> buffer, i.e., you use alloc_pages_node() for one page at a time, and >> then you stitch them on demand via SW? > > Not for BTS, it wants a linear range, getting the vmalloc vs NMI thing > sorted would be best I think. > What is annoying in this is that you run into the problem even though you may not be using BTS nor PEBS.
What mitigates the problem, I think, is the NMI watchdog. It is the first user of perf_events. As such, the BTS and PEBS buffers get allocated during kernel initialization thereby increasing the chances of finding contiguous chunks of memory. What would partly help would be to use of kmalloc_node() to at least balance allocations amongst the various NUMA nodes. That would be until the vmalloc() vs. NMI is sorted out. ------------------------------------------------------------------------------ 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
