On Tue, 22 May 2007 11:20:03 -0700 Fenghua Yu <[EMAIL PROTECTED]> wrote:
> per cpu data section contains two types of data. One set which is exclusively > accessed by the local cpu and the other set which is per cpu, but also shared > by remote cpus. In the current kernel, these two sets are not clearely > separated out. This can potentially cause the same data cacheline shared > between the two sets of data, which will result in unnecessary bouncing of the > cacheline between cpus. > > One way to fix the problem is to cacheline align the remotely accessed per cpu > data, both at the beginning and at the end. Because of the padding at both > ends, > this will likely cause some memory wastage and also the interface to achieve > this is not clean. > > This patch: > > Moves the remotely accessed per cpu data (which is currently marked > as ____cacheline_aligned_in_smp) into a different section, where all the data > elements are cacheline aligned. And as such, this differentiates the local > only data and remotely accessed data cleanly. OK, but could we please have a concise description of the impact of these changes on kernel memory footprint? Increase or decrease? And by approximately how much? Thanks. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
