when run the folloing command under shell, it will return error sh/$ echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad address
After strace, I found the following log: ... write(1, "1\n", 2) = 3 write(1, "", 4294967295) = -1 EFAULT (Bad address) write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address ) = 31 This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory. The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from sysctl_compaction_handler after compaction_nodes finished. Suggested-by:David Rientjes <rient...@google.com> Cc:Mel Gorman <mgor...@suse.de> Cc:Andrew Morton <a...@linux-foundation.org> Cc:Rik van Riel <r...@redhat.com> Cc:Minchan Kim <minc...@kernel.org> Cc:KAMEZAWA Hiroyuki <kamezawa.hir...@jp.fujitsu.com> Signed-off-by: Jason Liu <r64...@freescale.com> --- mm/compaction.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1210,7 +1210,7 @@ static int compact_node(int nid) } /* Compact all nodes in the system */ -static int compact_nodes(void) +static void compact_nodes(void) { int nid; @@ -1219,8 +1219,6 @@ static int compact_nodes(void) for_each_online_node(nid) compact_node(nid); - - return COMPACT_COMPLETE; } /* The written value is actually unused, all memory is compacted */ @@ -1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { if (write) - return compact_nodes(); + compact_nodes(); return 0; } -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/