From: David Hildenbrand <david@redhat.com> mainline inclusion from linux-5.7-rc1 commit 5f47adf762b78cae97de58d9ff01d2d44db09467 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S CVE: NA -------------------------------- For now, distributions implement advanced udev rules to essentially - Don't online any hotplugged memory (s390x) - Online all memory to ZONE_NORMAL (e.g., most virt environments like hyperv) - Online all memory to ZONE_MOVABLE in case the zone imbalance is taken care of (e.g., bare metal, special virt environments) In summary: All memory is usually onlined the same way, however, the kernel always has to ask user space to come up with the same answer. E.g., Hyper-V always waits for a memory block to get onlined before continuing, otherwise it might end up adding memory faster than onlining it, which can result in strange OOM situations. This waiting slows down adding of a bigger amount of memory. Let's allow to specify a default online_type, not just "online" and "offline". This allows distributions to configure the default online_type when booting up and be done with it. We can now specify "offline", "online", "online_movable" and "online_kernel" via - "memhp_default_state=" on the kernel cmdline - /sys/devices/system/memory/auto_online_blocks just like we are able to specify for a single memory block via /sys/devices/system/memory/memoryX/state Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-9-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/base/memory.c | 11 +++++------ include/linux/memory_hotplug.h | 2 ++ mm/memory_hotplug.c | 8 ++++---- 3 files changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index f7c41be57976b..1b97f305173fb 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -37,7 +37,7 @@ static const char *const online_type_to_str[] = { [MMOP_ONLINE_MOVABLE] = "online_movable", }; -static int memhp_online_type_from_str(const char *str) +int memhp_online_type_from_str(const char *str) { int i; @@ -481,13 +481,12 @@ static ssize_t auto_online_blocks_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - if (sysfs_streq(buf, "online")) - memhp_default_online_type = MMOP_ONLINE; - else if (sysfs_streq(buf, "offline")) - memhp_default_online_type = MMOP_OFFLINE; - else + const int online_type = memhp_online_type_from_str(buf); + + if (online_type < 0) return -EINVAL; + memhp_default_online_type = online_type; return count; } diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 1ba6a688094de..bc433d459c861 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -105,6 +105,8 @@ extern void __online_page_free(struct page *page); extern int try_online_node(int nid); extern bool memhp_auto_online; +extern int memhp_online_type_from_str(const char *str); + /* Default online_type (MMOP_*) when new memory blocks are added. */ extern int memhp_default_online_type; /* If movable_node boot option specified */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 3b9d409c902b9..3df9285b73b18 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -78,10 +78,10 @@ EXPORT_SYMBOL_GPL(memhp_auto_online); static int __init setup_memhp_default_state(char *str) { - if (!strcmp(str, "online")) - memhp_default_online_type = MMOP_ONLINE; - else if (!strcmp(str, "offline")) - memhp_default_online_type = MMOP_OFFLINE; + const int online_type = memhp_online_type_from_str(str); + + if (online_type >= 0) + memhp_default_online_type = online_type; return 1; } -- 2.25.1