From: Vasily Gorbik <gor@linux.ibm.com> stable inclusion from stable-v5.10.84 commit 03957229053119e3359e866a5ccb0df0bfe0195e bugzilla: 186030 https://gitee.com/openeuler/kernel/issues/I4QV2F Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 5dbc4cb4667457b0c53bcd7bff11500b3c362975 ] There is a difference in how architectures treat "mem=" option. For some that is an amount of online memory, for s390 and x86 this is the limiting max address. Some memblock api like memblock_enforce_memory_limit() take limit argument and explicitly treat it as the size of online memory, and use __find_max_addr to convert it to an actual max address. Current s390 usage: memblock_enforce_memory_limit(memblock_end_of_DRAM()); yields different results depending on presence of memory holes (offline memory blocks in between online memory). If there are no memory holes limit == max_addr in memblock_enforce_memory_limit() and it does trim online memory and reserved memory regions. With memory holes present it actually does nothing. Since we already use memblock_remove() explicitly to trim online memory regions to potential limit (think mem=, kdump, addressing limits, etc.) drop the usage of memblock_enforce_memory_limit() altogether. Trimming reserved regions should not be required, since we now use memblock_set_current_limit() to limit allocations and any explicit memory reservations above the limit is an actual problem we should not hide. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- arch/s390/kernel/setup.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 5cd9d20af31e..f9f8721dc532 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -845,9 +845,6 @@ static void __init setup_memory(void) storage_key_init_range(start, end); psw_set_key(PAGE_DEFAULT_KEY); - - /* Only cosmetics */ - memblock_enforce_memory_limit(memblock_end_of_DRAM()); } /* -- 2.20.1