From: Yasuaki Ishimatsu <[email protected]> If system supports memory hot-remove, online_pages() may online removed pages. So online_pages() need to check whether onlining pages are present or not.
CC: David Rientjes <[email protected]> CC: Jiang Liu <[email protected]> CC: Len Brown <[email protected]> CC: Benjamin Herrenschmidt <[email protected]> CC: Paul Mackerras <[email protected]> CC: Christoph Lameter <[email protected]> Cc: Minchan Kim <[email protected]> CC: Andrew Morton <[email protected]> CC: KOSAKI Motohiro <[email protected]> CC: Wen Congyang <[email protected]> Signed-off-by: Yasuaki Ishimatsu <[email protected]> --- include/linux/mmzone.h | 19 +++++++++++++++++++ mm/memory_hotplug.c | 13 +++++++++++++ 2 files changed, 32 insertions(+), 0 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 2daa54f..ac3ae30 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1180,6 +1180,25 @@ void sparse_init(void); #define sparse_index_init(_sec, _nid) do {} while (0) #endif /* CONFIG_SPARSEMEM */ +#ifdef CONFIG_SPARSEMEM +static inline int pfns_present(unsigned long pfn, unsigned long nr_pages) +{ + int i; + for (i = 0; i < nr_pages; i++) { + if (pfn_present(pfn + i)) + continue; + else + return -EINVAL; + } + return 0; +} +#else +static inline int pfns_present(unsigned long pfn, unsigned long nr_pages) +{ + return 0; +} +#endif /* CONFIG_SPARSEMEM*/ + #ifdef CONFIG_NODES_SPAN_OTHER_NODES bool early_pfn_in_nid(unsigned long pfn, int nid); #else diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 80cded7..3f1d7c5 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -467,6 +467,19 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages) struct memory_notify arg; lock_memory_hotplug(); + /* + * If system supports memory hot-remove, the memory may have been + * removed. So we check whether the memory has been removed or not. + * + * Note: When CONFIG_SPARSEMEM is defined, pfns_present() become + * effective. If CONFIG_SPARSEMEM is not defined, pfns_present() + * always returns 0. + */ + ret = pfns_present(pfn, nr_pages); + if (ret) { + unlock_memory_hotplug(); + return ret; + } arg.start_pfn = pfn; arg.nr_pages = nr_pages; arg.status_change_nid = -1; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
