a?? 2015/10/10 17:27, Hillf Danton a??e??: >> From: Changsheng Liu >> >> After the user config CONFIG_MOVABLE_NODE, >> When the memory is hot added, should_add_memory_movable() return 0 >> because all zones including movable zone are empty, >> so the memory that was hot added will be added to the normal zone >> and the normal zone will be created firstly. >> But we want the whole node to be added to movable zone defaultly. >> >> So we change should_add_memory_movable(): if the user config >> CONFIG_MOVABLE_NODE and sysctl parameter hotadd_memory_as_movable and >> the ZONE_NORMAL is empty or the pfn of the hot-added memory >> is after the end of the ZONE_NORMAL it will always return 1 >> and all zones is empty at the same time, >> so that the movable zone will be created firstly >> and then the whole node will be added to movable zone defaultly. >> If we want the node to be added to normal zone, >> we can do it as follows: >> "echo online_kernel > /sys/devices/system/memory/memoryXXX/state" >> >> Signed-off-by: Changsheng Liu >> Signed-off-by: Xiaofeng Yan >> Tested-by: Dongdong Fan >> Cc: Wang Nan >> Cc: Zhang Yanfei >> Cc: Dave Hansen >> Cc: Yinghai Lu >> Cc: Tang Chen >> Cc: Hu Tao >> Cc: Lai Jiangshan >> Cc: Yasuaki Ishimatsu >> Cc: Gu Zheng >> Cc: Toshi Kani >> Cc: Xishi Qiu >> Signed-off-by: Andrew Morton > Hm... by AKPM, Advanced kernel Programming Master, really? Sorry about my negligence,I will update the patch.Thanks for reminding me. >> --- >> Documentation/memory-hotplug.txt | 5 ++++- >> kernel/sysctl.c | 15 +++++++++++++++ >> mm/memory_hotplug.c | 23 +++++++++++++++++++++++ >> 3 files changed, 42 insertions(+), 1 deletions(-) >> >> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt >> index ce2cfcf..7e6b4f4 100644 >> --- a/Documentation/memory-hotplug.txt >> +++ b/Documentation/memory-hotplug.txt >> @@ -277,7 +277,7 @@ And if the memory block is in ZONE_MOVABLE, you can change it to ZONE_NORMAL: >> After this, memory block XXX's state will be 'online' and the amount of >> available memory will be increased. >> >> -Currently, newly added memory is added as ZONE_NORMAL (for powerpc, ZONE_DMA). >> +Currently, newly added memory is added as ZONE_NORMAL or ZONE_MOVABLE (for powerpc, ZONE_DMA). >> This may be changed in future. >> >> >> @@ -319,6 +319,9 @@ creates ZONE_MOVABLE as following. >> Size of memory not for movable pages (not for offline) is TOTAL - ZZZZ. >> Size of memory for movable pages (for offline) is ZZZZ. >> >> +And a sysctl parameter for assigning the hot added memory to ZONE_MOVABLE is >> +supported. If the value of "kernel/hotadd_memory_as_movable" is 1,the hot added >> +memory will be assigned to ZONE_MOVABLE defautly. >> >> Note: Unfortunately, there is no information to show which memory block belongs >> to ZONE_MOVABLE. This is TBD. >> diff --git a/kernel/sysctl.c b/kernel/sysctl.c >> index 19b62b5..855c48e 100644 >> --- a/kernel/sysctl.c >> +++ b/kernel/sysctl.c >> @@ -166,6 +166,10 @@ extern int unaligned_dump_stack; >> extern int no_unaligned_warning; >> #endif >> >> +#ifdef CONFIG_MOVABLE_NODE >> +extern int hotadd_memory_as_movable; >> +#endif >> + >> #ifdef CONFIG_PROC_SYSCTL >> >> #define SYSCTL_WRITES_LEGACY -1 >> @@ -1139,6 +1143,17 @@ static struct ctl_table kern_table[] = { >> .proc_handler = timer_migration_handler, >> }, >> #endif >> +/*If the value of "kernel/hotadd_memory_as_movable" is 1,the hot added >> + * memory will be assigned to ZONE_MOVABLE defautly.*/ >> +#ifdef CONFIG_MOVABLE_NODE >> + { >> + .procname = "hotadd_memory_as_movable", >> + .data = &hotadd_memory_as_movable, >> + .maxlen = sizeof(int), >> + .mode = 0644, >> + .proc_handler = proc_dointvec, >> + }, >> +#endif >> { } >> }; >> >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index 26fbba7..5bcaf74 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -37,6 +37,10 @@ >> >> #include "internal.h" >> >> +/*If the global variable value is 1, >> + * the hot added memory will be assigned to ZONE_MOVABLE defautly*/ >> +int hotadd_memory_as_movable; >> + >> /* >> * online_page_callback contains pointer to current page onlining function. >> * Initially it is generic_online_page(). If it is required it could be >> @@ -1190,6 +1194,9 @@ static int check_hotplug_memory_range(u64 start, u64 size) >> /* >> * If movable zone has already been setup, newly added memory should be check. >> * If its address is higher than movable zone, it should be added as movable. >> + * And if system config CONFIG_MOVABLE_NODE and set the sysctl parameter >> + * "hotadd_memory_as_movable" and added memory does not overlap the zone >> + * before MOVABLE_ZONE,the memory is added as movable. >> * Without this check, movable zone may overlap with other zone. >> */ >> static int should_add_memory_movable(int nid, u64 start, u64 size) >> @@ -1197,6 +1204,22 @@ static int should_add_memory_movable(int nid, u64 start, u64 size) >> unsigned long start_pfn = start >> PAGE_SHIFT; >> pg_data_t *pgdat = NODE_DATA(nid); >> struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE; >> + struct zone *pre_zone = pgdat->node_zones + (ZONE_MOVABLE - 1); >> + /* >> + * The system configs CONFIG_MOVABLE_NODE to assign a node >> + * which has only movable memory,so the hot-added memory should >> + * be assigned to ZONE_MOVABLE defaultly, >> + * but the function zone_for_memory() assign the hot-added memory >> + * to ZONE_NORMAL(x86_64) defaultly.Kernel does not allow to >> + * create ZONE_MOVABLE before ZONE_NORMAL,so If the value of >> + * sysctl parameter "hotadd_memory_as_movable" is 1 >> + * and the ZONE_NORMAL is empty or the pfn of the hot-added memory >> + * is after the end of the ZONE_NORMAL >> + * the hot-added memory will be assigned to ZONE_MOVABLE. >> + */ >> + if (hotadd_memory_as_movable >> + && (zone_is_empty(pre_zone) || zone_end_pfn(pre_zone) <= start_pfn)) >> + return 1; >> >> if (zone_is_empty(movable_zone)) >> return 0; >> -- >> 1.7.1 > . >