Re: [PATCH -next 2/3] mm: speed up mremap by 20x on large regions (v4)

Hi Joel, Thank you for the patch! Yet something to improve: [auto build test ERROR on next-20181102] url: https://github.com/0day-ci/linux/commits/Joel-Fernandes/Add-support-for-fast-mremap/20181103-224908 config: openrisc-or1ksim_defconfig (attached as .config) compiler: or1k-linux-gcc (GCC

Re: [PATCH -next 2/3] mm: speed up mremap by 20x on large regions (v4)

Hi Joel, Thank you for the patch! Yet something to improve: [auto build test ERROR on next-20181102] url: https://github.com/0day-ci/linux/commits/Joel-Fernandes/Add-support-for-fast-mremap/20181103-224908 config: xtensa-allmodconfig (attached as .config) compiler: xtensa-linux-gcc (GCC) 8.1

[PATCH -next 2/3] mm: speed up mremap by 20x on large regions (v4)

From: "Joel Fernandes (Google)" Android needs to mremap large regions of memory during memory management related operations. The mremap system call can be really slow if THP is not enabled. The bottleneck is move_page_tables, which is copying each pte at a time, and can be really slow across a la