Zhang, Xiantao wrote: >>From 697d50286088e98da5ac8653c80aaa96c81abf87 Mon Sep 17 00:00:00 2001 > From: Xiantao Zhang <xiantao.zhang@xxxxxxxxx> > Date: Mon, 31 Mar 2008 09:50:24 +0800 > Subject: [PATCH] KVM:IA64: Implement smp_call_function_mask for ia64 > > This function provides more flexible interface for smp > infrastructure. > Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx> Hi Xiantao, I'm a little wary of the performance impact of this change. Doing a cpumask compare on all smp_call_function calls seems a little expensive. Maybe it's just noise in the big picture compared to the actual cost of the IPIs, but I thought I'd bring it up. Keep in mind that a cpumask can be fairly big these days, max NR_CPUS is currently 4096. For those booting a kernel with NR_CPUS at 4096 on a dual CPU machine, it would be a bit expensive. Why not keep smp_call_function() the way it was before, rather than implementing it via the call to smp_call_function_mask()? Cheers, Jes _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
