| Message ID | 20200827234202.4027996-1-yuzhao@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] mm: use add_page_to_lru_list()/page_lru()/page_off_lru() | expand |
On Thu, Aug 27, 2020 at 05:42:01PM -0600, Yu Zhao wrote: > This is a trivial but worth having clean-up patch. There should be > no side effects except page->lru is temporarily poisoned after it's > deleted but before it's added to the new list in move_pages_to_lru() > (which is not a problem). > > Signed-off-by: Yu Zhao <yuzhao@google.com> Hi Alex, I just realized your [v18,08/32] mm/vmscan: remove unnecessary lruvec adding at https://patchwork.kernel.org/patch/11733123/ also touches move_pages_to_lru(). I agree it's better not to add a page we are going to free to the list in the first place. The rest in this patch would be too trivial to be a separate one (on top of yours). So would you mind taking of the clean-up too in your series? I'll drop this one then. Thanks. > --- > mm/swap.c | 4 +--- > mm/vmscan.c | 14 ++++---------- > 2 files changed, 5 insertions(+), 13 deletions(-) > > diff --git a/mm/swap.c b/mm/swap.c > index 40bf20a75278..2735ecf0f566 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -597,11 +597,9 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, > { > if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && > !PageSwapCache(page) && !PageUnevictable(page)) { > - bool active = PageActive(page); > int nr_pages = thp_nr_pages(page); > > - del_page_from_lru_list(page, lruvec, > - LRU_INACTIVE_ANON + active); > + del_page_from_lru_list(page, lruvec, page_lru(page)); > ClearPageActive(page); > ClearPageReferenced(page); > /* > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 99e1796eb833..b479ced26cd3 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1845,13 +1845,12 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > int nr_pages, nr_moved = 0; > LIST_HEAD(pages_to_free); > struct page *page; > - enum lru_list lru; > > while (!list_empty(list)) { > page = lru_to_page(list); > VM_BUG_ON_PAGE(PageLRU(page), page); > + list_del(&page->lru); > if (unlikely(!page_evictable(page))) { > - list_del(&page->lru); > spin_unlock_irq(&pgdat->lru_lock); > putback_lru_page(page); > spin_lock_irq(&pgdat->lru_lock); > @@ -1860,16 +1859,10 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > lruvec = mem_cgroup_page_lruvec(page, pgdat); > > SetPageLRU(page); > - lru = page_lru(page); > - > - nr_pages = thp_nr_pages(page); > - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > - list_move(&page->lru, &lruvec->lists[lru]); > + add_page_to_lru_list(page, lruvec, page_lru(page)); > > if (put_page_testzero(page)) { > - __ClearPageLRU(page); > - __ClearPageActive(page); > - del_page_from_lru_list(page, lruvec, lru); > + del_page_from_lru_list(page, lruvec, page_off_lru(page)); > > if (unlikely(PageCompound(page))) { > spin_unlock_irq(&pgdat->lru_lock); > @@ -1878,6 +1871,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > } else > list_add(&page->lru, &pages_to_free); > } else { > + nr_pages = thp_nr_pages(page); > nr_moved += nr_pages; > if (PageActive(page)) > workingset_age_nonresident(lruvec, nr_pages); > -- > 2.28.0.402.g5ffc5be6b7-goog >
在 2020/8/30 上午2:12, Yu Zhao 写道: > On Thu, Aug 27, 2020 at 05:42:01PM -0600, Yu Zhao wrote: >> This is a trivial but worth having clean-up patch. There should be >> no side effects except page->lru is temporarily poisoned after it's >> deleted but before it's added to the new list in move_pages_to_lru() >> (which is not a problem). >> >> Signed-off-by: Yu Zhao <yuzhao@google.com> > > Hi Alex, I just realized your > [v18,08/32] mm/vmscan: remove unnecessary lruvec adding > at > https://patchwork.kernel.org/patch/11733123/ > also touches move_pages_to_lru(). I agree it's better not to add > a page we are going to free to the list in the first place. The > rest in this patch would be too trivial to be a separate one (on > top of yours). > > So would you mind taking of the clean-up too in your series? I'll > drop this one then. Thanks. > >> --- >> mm/swap.c | 4 +--- >> mm/vmscan.c | 14 ++++---------- >> 2 files changed, 5 insertions(+), 13 deletions(-) >> >> diff --git a/mm/swap.c b/mm/swap.c >> index 40bf20a75278..2735ecf0f566 100644 >> --- a/mm/swap.c >> +++ b/mm/swap.c >> @@ -597,11 +597,9 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, >> { >> if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && >> !PageSwapCache(page) && !PageUnevictable(page)) { >> - bool active = PageActive(page); >> int nr_pages = thp_nr_pages(page); >> >> - del_page_from_lru_list(page, lruvec, >> - LRU_INACTIVE_ANON + active); >> + del_page_from_lru_list(page, lruvec, page_lru(page)); >> ClearPageActive(page); >> ClearPageReferenced(page); >> /* >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index 99e1796eb833..b479ced26cd3 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -1845,13 +1845,12 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, >> int nr_pages, nr_moved = 0; >> LIST_HEAD(pages_to_free); >> struct page *page; >> - enum lru_list lru; >> >> while (!list_empty(list)) { >> page = lru_to_page(list); >> VM_BUG_ON_PAGE(PageLRU(page), page); >> + list_del(&page->lru); >> if (unlikely(!page_evictable(page))) { >> - list_del(&page->lru); >> spin_unlock_irq(&pgdat->lru_lock); >> putback_lru_page(page); >> spin_lock_irq(&pgdat->lru_lock); >> @@ -1860,16 +1859,10 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, >> lruvec = mem_cgroup_page_lruvec(page, pgdat); >> >> SetPageLRU(page); >> - lru = page_lru(page); >> - >> - nr_pages = thp_nr_pages(page); >> - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); >> - list_move(&page->lru, &lruvec->lists[lru]); >> + add_page_to_lru_list(page, lruvec, page_lru(page)); >> >> if (put_page_testzero(page)) { >> - __ClearPageLRU(page); it's interesting to know the PageLRU left has no bad impact in real life. it justs seems a path confliction with my that patch. >> - __ClearPageActive(page); >> - del_page_from_lru_list(page, lruvec, lru); >> + del_page_from_lru_list(page, lruvec, page_off_lru(page)); >> >> if (unlikely(PageCompound(page))) { >> spin_unlock_irq(&pgdat->lru_lock); >> @@ -1878,6 +1871,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, >> } else >> list_add(&page->lru, &pages_to_free); >> } else { >> + nr_pages = thp_nr_pages(page); >> nr_moved += nr_pages; >> if (PageActive(page)) >> workingset_age_nonresident(lruvec, nr_pages); >> -- >> 2.28.0.402.g5ffc5be6b7-goog >>
On Sun, Aug 30, 2020 at 04:31:38PM +0800, Alex Shi wrote: > > > 在 2020/8/30 上午2:12, Yu Zhao 写道: > > On Thu, Aug 27, 2020 at 05:42:01PM -0600, Yu Zhao wrote: > >> This is a trivial but worth having clean-up patch. There should be > >> no side effects except page->lru is temporarily poisoned after it's > >> deleted but before it's added to the new list in move_pages_to_lru() > >> (which is not a problem). > >> > >> Signed-off-by: Yu Zhao <yuzhao@google.com> > > > > Hi Alex, I just realized your > > [v18,08/32] mm/vmscan: remove unnecessary lruvec adding > > at > > https://patchwork.kernel.org/patch/11733123/ > > also touches move_pages_to_lru(). I agree it's better not to add > > a page we are going to free to the list in the first place. The > > rest in this patch would be too trivial to be a separate one (on > > top of yours). > > > > So would you mind taking of the clean-up too in your series? I'll > > drop this one then. Thanks. Ok, maybe I wasn't clear before. Please see what exactly I'm asking you to consider below. > >> diff --git a/mm/swap.c b/mm/swap.c > >> index 40bf20a75278..2735ecf0f566 100644 > >> --- a/mm/swap.c > >> +++ b/mm/swap.c > >> @@ -597,11 +597,9 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, > >> { > >> if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && > >> !PageSwapCache(page) && !PageUnevictable(page)) { > >> - bool active = PageActive(page); > >> int nr_pages = thp_nr_pages(page); > >> > >> - del_page_from_lru_list(page, lruvec, > >> - LRU_INACTIVE_ANON + active); > >> + del_page_from_lru_list(page, lruvec, page_lru(page)); > >> ClearPageActive(page); > >> ClearPageReferenced(page); > >> /* 1) The above has no conflict with your series and therefore can go separately. Feel free to include it. > >> diff --git a/mm/vmscan.c b/mm/vmscan.c > >> index 99e1796eb833..b479ced26cd3 100644 > >> --- a/mm/vmscan.c > >> +++ b/mm/vmscan.c > >> @@ -1845,13 +1845,12 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > >> int nr_pages, nr_moved = 0; > >> LIST_HEAD(pages_to_free); > >> struct page *page; > >> - enum lru_list lru; > >> > >> while (!list_empty(list)) { > >> page = lru_to_page(list); > >> VM_BUG_ON_PAGE(PageLRU(page), page); > >> + list_del(&page->lru); > >> if (unlikely(!page_evictable(page))) { > >> - list_del(&page->lru); > >> spin_unlock_irq(&pgdat->lru_lock); > >> putback_lru_page(page); > >> spin_lock_irq(&pgdat->lru_lock); 2) The above is the same change you've made. > >> @@ -1860,16 +1859,10 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > >> lruvec = mem_cgroup_page_lruvec(page, pgdat); > >> > >> SetPageLRU(page); > >> - lru = page_lru(page); > >> - > >> - nr_pages = thp_nr_pages(page); > >> - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > >> - list_move(&page->lru, &lruvec->lists[lru]); > >> + add_page_to_lru_list(page, lruvec, page_lru(page)); > >> > >> if (put_page_testzero(page)) { > >> - __ClearPageLRU(page); > > it's interesting to know the PageLRU left has no bad impact in real life. > it justs seems a path confliction with my that patch. (No, we can't leave PG_lru uncleared. It's done by the page_off_lru() right below). > >> - __ClearPageActive(page); > >> - del_page_from_lru_list(page, lruvec, lru); > >> + del_page_from_lru_list(page, lruvec, page_off_lru(page)); > >> > >> if (unlikely(PageCompound(page))) { > >> spin_unlock_irq(&pgdat->lru_lock); > >> @@ -1878,6 +1871,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > >> } else > >> list_add(&page->lru, &pages_to_free); > >> } else { > >> + nr_pages = thp_nr_pages(page); > >> nr_moved += nr_pages; > >> if (PageActive(page)) > >> workingset_age_nonresident(lruvec, nr_pages); 3) The above is the conflict. Since we won't add and then delete a page after your patch, we won't need it. But I do want this (you've snipped from your reply, so I take that you already figured it out): - lru = page_lru(page); - - nr_pages = thp_nr_pages(page); - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); - list_move(&page->lru, &lruvec->lists[lru]); + add_page_to_lru_list(page, lruvec, page_lru(page)); No worries if you prefer this to go separately too.
On Sun, Aug 30, 2020 at 05:44:04PM -0600, Yu Zhao wrote: > On Sun, Aug 30, 2020 at 04:31:38PM +0800, Alex Shi wrote: > > > > > > 在 2020/8/30 上午2:12, Yu Zhao 写道: > > > On Thu, Aug 27, 2020 at 05:42:01PM -0600, Yu Zhao wrote: > > >> This is a trivial but worth having clean-up patch. There should be > > >> no side effects except page->lru is temporarily poisoned after it's > > >> deleted but before it's added to the new list in move_pages_to_lru() > > >> (which is not a problem). > > >> > > >> Signed-off-by: Yu Zhao <yuzhao@google.com> > > > > > > Hi Alex, I just realized your > > > [v18,08/32] mm/vmscan: remove unnecessary lruvec adding > > > at > > > https://patchwork.kernel.org/patch/11733123/ > > > also touches move_pages_to_lru(). I agree it's better not to add > > > a page we are going to free to the list in the first place. The > > > rest in this patch would be too trivial to be a separate one (on > > > top of yours). > > > > > > So would you mind taking of the clean-up too in your series? I'll > > > drop this one then. Thanks. > > Ok, maybe I wasn't clear before. Please see what exactly I'm asking > you to consider below. > > > >> diff --git a/mm/swap.c b/mm/swap.c > > >> index 40bf20a75278..2735ecf0f566 100644 > > >> --- a/mm/swap.c > > >> +++ b/mm/swap.c > > >> @@ -597,11 +597,9 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, > > >> { > > >> if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && > > >> !PageSwapCache(page) && !PageUnevictable(page)) { > > >> - bool active = PageActive(page); > > >> int nr_pages = thp_nr_pages(page); > > >> > > >> - del_page_from_lru_list(page, lruvec, > > >> - LRU_INACTIVE_ANON + active); > > >> + del_page_from_lru_list(page, lruvec, page_lru(page)); > > >> ClearPageActive(page); > > >> ClearPageReferenced(page); > > >> /* > > 1) The above has no conflict with your series and therefore can go > separately. Feel free to include it. > > > >> diff --git a/mm/vmscan.c b/mm/vmscan.c > > >> index 99e1796eb833..b479ced26cd3 100644 > > >> --- a/mm/vmscan.c > > >> +++ b/mm/vmscan.c > > >> @@ -1845,13 +1845,12 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > > >> int nr_pages, nr_moved = 0; > > >> LIST_HEAD(pages_to_free); > > >> struct page *page; > > >> - enum lru_list lru; > > >> > > >> while (!list_empty(list)) { > > >> page = lru_to_page(list); > > >> VM_BUG_ON_PAGE(PageLRU(page), page); > > >> + list_del(&page->lru); > > >> if (unlikely(!page_evictable(page))) { > > >> - list_del(&page->lru); > > >> spin_unlock_irq(&pgdat->lru_lock); > > >> putback_lru_page(page); > > >> spin_lock_irq(&pgdat->lru_lock); > > 2) The above is the same change you've made. > > > >> @@ -1860,16 +1859,10 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > > >> lruvec = mem_cgroup_page_lruvec(page, pgdat); > > >> > > >> SetPageLRU(page); > > >> - lru = page_lru(page); > > >> - > > >> - nr_pages = thp_nr_pages(page); > > >> - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > > >> - list_move(&page->lru, &lruvec->lists[lru]); > > >> + add_page_to_lru_list(page, lruvec, page_lru(page)); > > >> > > >> if (put_page_testzero(page)) { > > >> - __ClearPageLRU(page); > > > > it's interesting to know the PageLRU left has no bad impact in real life. > > it justs seems a path confliction with my that patch. > > (No, we can't leave PG_lru uncleared. It's done by the page_off_lru() > right below). Sorry about this false claim. You are right: we need to keep __ClearPageLRU() here. page_off_lru() doesn't do it for us. I'll fix this in v2. Thanks.
diff --git a/mm/swap.c b/mm/swap.c index 40bf20a75278..2735ecf0f566 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -597,11 +597,9 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, { if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && !PageSwapCache(page) && !PageUnevictable(page)) { - bool active = PageActive(page); int nr_pages = thp_nr_pages(page); - del_page_from_lru_list(page, lruvec, - LRU_INACTIVE_ANON + active); + del_page_from_lru_list(page, lruvec, page_lru(page)); ClearPageActive(page); ClearPageReferenced(page); /* diff --git a/mm/vmscan.c b/mm/vmscan.c index 99e1796eb833..b479ced26cd3 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1845,13 +1845,12 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, int nr_pages, nr_moved = 0; LIST_HEAD(pages_to_free); struct page *page; - enum lru_list lru; while (!list_empty(list)) { page = lru_to_page(list); VM_BUG_ON_PAGE(PageLRU(page), page); + list_del(&page->lru); if (unlikely(!page_evictable(page))) { - list_del(&page->lru); spin_unlock_irq(&pgdat->lru_lock); putback_lru_page(page); spin_lock_irq(&pgdat->lru_lock); @@ -1860,16 +1859,10 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, lruvec = mem_cgroup_page_lruvec(page, pgdat); SetPageLRU(page); - lru = page_lru(page); - - nr_pages = thp_nr_pages(page); - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); - list_move(&page->lru, &lruvec->lists[lru]); + add_page_to_lru_list(page, lruvec, page_lru(page)); if (put_page_testzero(page)) { - __ClearPageLRU(page); - __ClearPageActive(page); - del_page_from_lru_list(page, lruvec, lru); + del_page_from_lru_list(page, lruvec, page_off_lru(page)); if (unlikely(PageCompound(page))) { spin_unlock_irq(&pgdat->lru_lock); @@ -1878,6 +1871,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, } else list_add(&page->lru, &pages_to_free); } else { + nr_pages = thp_nr_pages(page); nr_moved += nr_pages; if (PageActive(page)) workingset_age_nonresident(lruvec, nr_pages);
This is a trivial but worth having clean-up patch. There should be no side effects except page->lru is temporarily poisoned after it's deleted but before it's added to the new list in move_pages_to_lru() (which is not a problem). Signed-off-by: Yu Zhao <yuzhao@google.com> --- mm/swap.c | 4 +--- mm/vmscan.c | 14 ++++---------- 2 files changed, 5 insertions(+), 13 deletions(-)