Re: [PATCHv9-rebased2 01/37] mm, thp: make swapin readahead under down_read of mmap_sem
From: Hillf Danton <hidden>
Date: 2016-06-20 03:12:17
Also in:
lkml
Possibly related (same subject, not in this thread)
- 2016-06-15 · [PATCHv9-rebased2 01/37] mm, thp: make swapin readahead under down_read of mmap_sem · Kirill A. Shutemov <hidden>
quoted
quoted
quoted
@@ -2401,11 +2430,18 @@ static void __collapse_huge_page_swapin(struct mm_struct *mm, continue; swapped_in++; ret = do_swap_page(mm, vma, _address, pte, pmd, - FAULT_FLAG_ALLOW_RETRY|FAULT_FLAG_RETRY_NOWAIT, + FAULT_FLAG_ALLOW_RETRY,Add a description in change log for it please.Ebru, would you address it?This changelog really seems poor. Is there a way to update only changelog of the commit? I tried to use git rebase to amend commit, however I could not rebase. This patch only needs better changelog. I would like to update it as follows, if you would like to too: " Currently khugepaged makes swapin readahead under down_write. This patch supplies to make swapin readahead under down_read instead of down_write. Along swapin, we can need to drop and re-take mmap_sem. Therefore we have to be sure vma is consistent. This patch adds a helper function to validate vma and also supplies that async swapin should not be performed without waiting. The patch was tested with a test program that allocates 800MB of memory, writes to it, and then sleeps. The system was forced to swap out all. Afterwards, the test program touches the area by writing, it skips a page in each 20 pages of the area. "
I like to ask again, why is FAULT_FLAG_RETRY_NOWAIT dropped?
Could you please suggest me a way to replace above changelog with the old?
We can ask Andrew for some advices.
quoted
quoted
They are cleaned up in subsequent darns?Yes, that is reported and fixed here: http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=fc7038a69cee6b817261f7cd805e9663fdc1075c However, the above comment inconsistency still there. I've added a fix patch: From 404438ff1b0617cbf7434cba0c5a08f79ccb8a5d Mon Sep 17 00:00:00 2001 From: Ebru Akagunduz <redacted> Date: Sat, 18 Jun 2016 21:07:22 +0300 Subject: [PATCH] mm, thp: fix comment inconsistency for swapin readahead functions
Fill in change log please. thanks Hillf
quoted hunk ↗ jump to hunk
Signed-off-by: Ebru Akagunduz <redacted> --- mm/huge_memory.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)diff --git a/mm/huge_memory.c b/mm/huge_memory.c index acd374e..f0d528e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c@@ -2436,9 +2436,10 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, /* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */ if (ret & VM_FAULT_RETRY) { down_read(&mm->mmap_sem); - /* vma is no longer available, don't continue to swapin */ - if (hugepage_vma_revalidate(mm, address)) + if (hugepage_vma_revalidate(mm, address)) { + /* vma is no longer available, don't continue to swapin */ return false; + } } if (ret & VM_FAULT_ERROR) { trace_mm_collapse_huge_page_swapin(mm, swapped_in, 0);@@ -2513,8 +2514,8 @@ static void collapse_huge_page(struct mm_struct *mm, if (allocstall == curr_allocstall && swap != 0) { /* * __collapse_huge_page_swapin always returns with mmap_sem - * locked. If it fails, release mmap_sem and jump directly - * out. Continuing to collapse causes inconsistency. + * locked. If it fails, we release mmap_sem and jump out_nolock. + * Continuing to collapse causes inconsistency. */ if (!__collapse_huge_page_swapin(mm, vma, address, pmd)) { mem_cgroup_cancel_charge(new_page, memcg, true); --1.9.1
-- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>