On Mon, 2010-09-13 at 16:55 +0200, Stephane Eranian wrote: > 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. > > All buffers are only accessed on the CPU they are attached to. > kzalloc() does not take into account NUMA, thus all allocations > are taking place on the NUMA node where the perf_event_open() is > made.
I guess that should have been a alloc_pages_node() indeed. > This patch switches allocation to vmalloc_node() to use non-contiguous > physical memory and to allocate on the NUMA node corresponding to each > CPU. We switched DS and PEBS although they do not cause problems today, > to, at least, make the allocation on the correct NUMA node. In the future, > the PEBS buffer size may increase. DS may also grow bigger than a page. > This patch eliminates the memory allocation imbalance. I'm not really a fan of vmalloc, have you actually observed allocation failures for these 64k (order-4) allocations? ------------------------------------------------------------------------------ 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
