On 2017/5/9 19:34, Vlastimil Babka wrote: > On 05/09/2017 12:55 PM, zhongjiang wrote: >> From: zhong jiang <zhongjiang@xxxxxxxxxx> >> >> Current, when we prepare a huge page to collapse, due to some >> reasons, it can fail to collapse. At the moment, we should >> release the preallocate huge page. >> >> Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx> > Hmm, scratch that, there's no memory leak. The pointer to new_page is > stored in *hpage, and put_page() is called all the way up in > khugepaged_do_scan(). I see. I miss it. but why the new_page need to be release all the way. I do not see the count increment when scan success. it save the memory, only when page fault happen. Thanks zhongjiang >> --- >> mm/khugepaged.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/mm/khugepaged.c b/mm/khugepaged.c >> index 7cb9c88..586b1f1 100644 >> --- a/mm/khugepaged.c >> +++ b/mm/khugepaged.c >> @@ -1082,6 +1082,8 @@ static void collapse_huge_page(struct mm_struct *mm, >> up_write(&mm->mmap_sem); >> out_nolock: >> trace_mm_collapse_huge_page(mm, isolated, result); >> + if (page != NULL && result != SCAN_SUCCEED) >> + put_page(new_page); >> return; >> out: >> mem_cgroup_cancel_charge(new_page, memcg, true); >> @@ -1555,6 +1557,8 @@ static void collapse_shmem(struct mm_struct *mm, >> } >> out: >> VM_BUG_ON(!list_empty(&pagelist)); >> + if (page != NULL && result != SCAN_SUCCEED) >> + put_page(new_page); >> /* TODO: tracepoints */ >> } >> >> > > . > -- 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>
