2012/10/02 18:42, Ni zhan Chen wrote: > On 10/02/2012 04:25 PM, Yasuaki Ishimatsu wrote: >> We are trying to implement a physical memory hot removing function as >> following thread. >> >> https://lkml.org/lkml/2012/9/5/201 >> >> But there is not enough review to merge into linux kernel. >> >> I think there are following blockades. >> 1. no physical memory hot removable system >> 2. huge patch-set >> >> If you have a KVM system, we can get rid of 1st blockade. Because >> applying following patch, we can create memory hot removable system >> on KVM guest. >> >> http://lists.gnu.org/archive/html/qemu-devel/2012-07/msg01389.html >> >> 2nd blockade is own problem. So we try to divide huge patch into >> a small patch in each function as follows: >> >> - bug fix >> - acpi framework >> - kernel core >> >> We had already sent bug fix patches. >> >> https://lkml.org/lkml/2012/9/27/39 >> >> And the patch fixes following bug. >> >> remove_memory() offlines memory. And it is called by following two cases: >> >> 1. echo offline >/sys/devices/system/memory/memoryXX/state >> 2. hot remove a memory device >> >> In the 1st case, the memory block's state is changed and the notification >> that memory block's state changed is sent to userland after calling >> offline_memory(). So user can notice memory block is changed., > > Hi Yasuaki, > > Thanks for splitting the patchset, it's more easier to review this time. > One question: > > How can notify userspace? you mean function node_memory_callback or > ...., but When calling memory_block_change_state(), it calls kobject_uevent(). This function notifies userspace of the online/offline notification. Thanks, Yasuaki Ishimatsu > this function basically do nothing. > >> >> But in the 2nd case, the memory block's state is not changed and the >> notification is not also sent to userspcae even if calling offline_memory(). >> So user cannot notice memory block is changed. >> >> We should also notify to userspace at 2nd case. >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@xxxxxxxxx. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>