4b3b4c5e64
__start_mcount_loc[] is unused after init, yet occupies RAM forever as part of .rodata. 152kiB is typical on a 64-bit architecture. Instead, __start_mcount_loc should be in the interval [__init_begin, __init_end) so that the space is reclaimed after init. __start_mcount_loc[] is generated during the load portion of kernel build, and is used only by ftrace_init(). ftrace_init is declared '__init' and is in .init.text, which is freed after init. __start_mcount_loc is placed into .rodata by a call to MCOUNT_REC inside the RO_DATA macro of include/asm-generic/vmlinux.lds.h. The array *is* read-only, but more importantly it is not used after init. So the call to MCOUNT_REC should be moved from RO_DATA to INIT_DATA. This patch has been tested on x86_64 with CONFIG_DEBUG_PAGEALLOC=y which verifies that the address range never is accessed after init. Signed-off-by: John Reiser <jreiser@BitWagon.com> LKML-Reference: <4A6DF0B6.7080402@bitwagon.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> |
||
|---|---|---|
| .. | ||
| acpi | ||
| asm-generic | ||
| crypto | ||
| drm | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| mtd | ||
| net | ||
| pcmcia | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| trace | ||
| video | ||
| xen | ||
| Kbuild | ||