On Tue, Jan 02, 2007 at 12:05:18PM +0100, Rene Herman wrote: > Good day. > > A while ago it was remarked on list here that keeping the kernel 4M > aligned physically might be a performance win if the added 1M (it > normally loads at 1M) meant it would fit on one 4M aligned hugepage > instead of 2 and since that time I've been doing such. > > In fact, while I was at it, I ran the kernel at 16M; while admittedly a > bit of a non-issue, having never experienced ZONE_DMA shortage, I am an > ISA user on a >16M machine so this seemed to make sense -- no kernel > eating up "precious" ISA-DMAable memory. > > Recently CONFIG_PHYSICAL_START was replaced by CONFIG_PHYSICAL_ALIGN > (commit e69f202d0a1419219198566e1c22218a5c71a9a6) and while 4M alignment > is still possible, that's also the strictest alignment allowed meaning I > can't load my (non-relocatable) kernel at 16M anymore. > > If I just apply the following and set it to 16M, things seem to be > working for me. Was there an important reason to limit the alignment to > 4M, and if so, even on non relocatable kernels?
Hi Rene, Can't think of any reason why we can't keep alignment uppper limit to 16M. That time I had kept 4M as upper limit as that seemed to be only practical usage. Rencetly I have restored back CONFIG_PHYSICAL_START option. That patch is still in -mm. IMHO, your case will fit more if we set CONFIG_PHYSICAL_START to 16M rather than increasing alignment upper limit for CONFIG_PHYSICAL_ALIGN. http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.20-rc2/2.6.20-rc2-mm1/broken-out/i386-restore-config_physical_start-option.patch Andrew, Can you please push this patch to 2.6.20-rc3? Thanks Vivek _______________________________________________ fastboot mailing list [email protected] https://lists.osdl.org/mailman/listinfo/fastboot
