While examining holes in percpu section I found this : c05f5000 D per_cpu__current_task c05f5000 D __per_cpu_start c05f5004 D per_cpu__cpu_number c05f5008 D per_cpu__irq_regs c05f500c d per_cpu__cpu_devices c05f5040 D per_cpu__cyc2ns c05f6000 d per_cpu__cpuid4_info c05f6004 d per_cpu__cache_kobject c05f6008 d per_cpu__index_kobject c05f7000 D per_cpu__gdt_page This is because gdt_page is a percpu variable, defined with a page alignement, and linker is doing its job, two times because of .o nesting in the build process. I introduced a new macro DEFINE_PER_CPU_PAGE_ALIGNED() to avoid wasting this space. All page aligned variables (only one at this time) are put in a separate subsection .data.percpu.page_aligned, at the very begining of percpu zone. Before patch , on a x86_32 machine : # size -A vmlinux.old vmlinux | grep percpu .data.percpu 30232 3227471872 .data.percpu 22168 3227471872 Thats 8064 bytes saved for each CPU. Patch against x86.git/latest Note : This will collide with Christoph efforts to put pda at offset 0 of percpu zone... Signed-off-by: Eric Dumazet arch/x86/kernel/cpu/common.c | 2 +- arch/x86/kernel/vmlinux_32.lds.S | 1 + include/asm-generic/vmlinux.lds.h | 1 + include/linux/percpu.h | 7 +++++++ 4 files changed, 10 insertions(+), 1 deletion(-)