On Mon, 9 Dec 2013 16:50:35 -0500 Santosh Shilimkar <santosh.shilimkar@xxxxxx> wrote: > Now the Nobootmem allocator will always try to free memory allocated for > reserved memory regions (free_low_memory_core_early()) without taking > into to account current memblock debugging configuration > (CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state). > As result if: > - CONFIG_DEBUG_FS defined > - CONFIG_ARCH_DISCARD_MEMBLOCK not defined; > - reserved memory regions array have been resized during boot > > then: > - memory allocated for reserved memory regions array will be freed to > buddy allocator; > - debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage > instead of state of memory reservations. like: > 0: 0x98393bc0..0x9a393bbf > 1: 0xff120000..0xff11ffff > 2: 0x00000000..0xffffffff > > Hence, do not free memory allocated for reserved memory regions if > defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK). Alternatives: - disable /proc/sys/kernel/debug/memblock/reserved in this case - disable defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK) in Kconfig. How much memory are we talking about here? If it's more than "very little" then I think either of these would be better - most users will value the extra memory over an accurate /proc/sys/kernel/debug/memblock/reserved? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>