On Fri, Nov 26, 2021 at 03:32:26PM +0800, Yang Wei wrote: > From: Yang Wei <yang.wei@xxxxxxxxxxxxxxxxx> > > We found _set_memory_array() and set_memory_array_wb() takes more than > 500ms in kernel space in the following scenario. > So use this patch to trigger schedule for each page, to avoid other > threads getting stuck. > > 0xffffffff810a34d2 find_next_iomem_res ([kernel.kallsyms]) > 0xffffffff810a3d40 walk_system_ram_range ([kernel.kallsyms]) > 0xffffffff810772ca pat_pagerange_is_ram ([kernel.kallsyms]) > 0xffffffff8107796f reserve_memtype ([kernel.kallsyms]) > 0xffffffff81075e98 _set_memory_array ([kernel.kallsyms]) > 0xffffffffc0ef6083 nv_alloc_system_pages [nvidia] ([kernel.kallsyms]) > > 0xffffffff810a34d2 find_next_iomem_res ([kernel.kallsyms]) > 0xffffffff810a3d40 walk_system_ram_range ([kernel.kallsyms]) > 0xffffffff810772ca pat_pagerange_is_ram ([kernel.kallsyms]) > 0xffffffff8107745a free_memtype.part.7 ([kernel.kallsyms]) > 0xffffffff8107606e set_memory_array_wb ([kernel.kallsyms]) > 0xffffffffc0ef6291 nv_free_system_pages [nvidia]([kernel.kallsyms]) > > Signed-off-by: Yang Wei <yang.wei@xxxxxxxxxxxxxxxxx> > Tested-by: Yang Wei <yang.wei@xxxxxxxxxxxxxxxxx> > --- > arch/x86/mm/pageattr.c | 2 ++ > 1 file changed, 2 insertions(+) Why is this 4.19-only? What commit in Linus's tree resolved this issue? confused, greg k-h
