From: Eric Dumazet We apparently hit the 1024 limit of vsyscall_0 zone when some debugging options are set, or if __vsyscall_gtod_data is 64 bytes larger. In order to save 128 bytes from the vsyscall_0 zone, we move __vgetcpu_mode & __jiffies to vsyscall_2 zone where they really belong, since they are used only from vgetcpu() (which is in this vsyscall_2 area). After patch is applied, new layout is : ffffffffff600000 T vgettimeofday ffffffffff60004e t vsysc2 ffffffffff600140 t vread_hpet ffffffffff600150 t vread_tsc ffffffffff600180 D __vsyscall_gtod_data ffffffffff600400 T vtime ffffffffff600413 t vsysc1 ffffffffff600800 T vgetcpu ffffffffff600870 D __vgetcpu_mode ffffffffff600880 D __jiffies ffffffffff600c00 T venosys_1 Signed-off-by: Eric Dumazet Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/x86_64/kernel/vmlinux.lds.S | 10 ++++++---- 1 files changed, 6 insertions(+), 4 deletions(-) diff -puN arch/x86_64/kernel/vmlinux.lds.S~x86_64-move-__vgetcpu_mode-__jiffies-to-the-vsyscall_2-zone arch/x86_64/kernel/vmlinux.lds.S --- a/arch/x86_64/kernel/vmlinux.lds.S~x86_64-move-__vgetcpu_mode-__jiffies-to-the-vsyscall_2-zone +++ a/arch/x86_64/kernel/vmlinux.lds.S @@ -95,6 +95,12 @@ SECTIONS { *(.vsyscall_gtod_data) } vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data); + + .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) + { *(.vsyscall_1) } + .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) + { *(.vsyscall_2) } + .vgetcpu_mode : AT(VLOAD(.vgetcpu_mode)) { *(.vgetcpu_mode) } vgetcpu_mode = VVIRT(.vgetcpu_mode); @@ -102,10 +108,6 @@ SECTIONS .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) } jiffies = VVIRT(.jiffies); - .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) - { *(.vsyscall_1) } - .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) - { *(.vsyscall_2) } .vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) { *(.vsyscall_3) } _