| Message ID | 155014053725.28944.7960592286711533914.stgit@localhost.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: Generalize putback functions | expand |
On Thu, Feb 14, 2019 at 01:35:37PM +0300, Kirill Tkhai wrote: > +static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > + struct list_head *list) > { > struct pglist_data *pgdat = lruvec_pgdat(lruvec); > + int nr_pages, nr_moved = 0; > LIST_HEAD(pages_to_free); > + struct page *page; > + enum lru_list lru; > > - /* > - * Put back any unfreeable pages. > - */ > - while (!list_empty(page_list)) { > - struct page *page = lru_to_page(page_list); > - int 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_init(&page->lru); Why change to list_del_init? It's more special than list_del but doesn't seem needed since the page is list_add()ed later. That postprocess script from patch 1 seems kinda broken before this series, and still is. Not that it should block this change. Out of curiosity did you get it to run?
On 15.02.2019 23:39, Daniel Jordan wrote: > On Thu, Feb 14, 2019 at 01:35:37PM +0300, Kirill Tkhai wrote: >> +static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, >> + struct list_head *list) >> { >> struct pglist_data *pgdat = lruvec_pgdat(lruvec); >> + int nr_pages, nr_moved = 0; >> LIST_HEAD(pages_to_free); >> + struct page *page; >> + enum lru_list lru; >> >> - /* >> - * Put back any unfreeable pages. >> - */ >> - while (!list_empty(page_list)) { >> - struct page *page = lru_to_page(page_list); >> - int 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_init(&page->lru); > > Why change to list_del_init? It's more special than list_del but doesn't seem > needed since the page is list_add()ed later. Not something special is here, I'll remove this _init. > That postprocess script from patch 1 seems kinda broken before this series, and > still is. Not that it should block this change. Out of curiosity did you get > it to run? I fixed all new warnings, which come with my changes, so the patch does not make the script worse. If you change all already existing warnings by renaming variables in appropriate places, the script will work in some way. But I'm not sure this is enough to get results correct, and I have no a big wish to dive into perl to fix warnings introduced by another people, so I don't plan to do with this script something else.
On Fri, Feb 15, 2019 at 10:01:05PM +0000, Kirill Tkhai wrote: > On 15.02.2019 23:39, Daniel Jordan wrote: > > On Thu, Feb 14, 2019 at 01:35:37PM +0300, Kirill Tkhai wrote: > >> +static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > >> + struct list_head *list) > >> { > >> struct pglist_data *pgdat = lruvec_pgdat(lruvec); > >> + int nr_pages, nr_moved = 0; > >> LIST_HEAD(pages_to_free); > >> + struct page *page; > >> + enum lru_list lru; > >> > >> - /* > >> - * Put back any unfreeable pages. > >> - */ > >> - while (!list_empty(page_list)) { > >> - struct page *page = lru_to_page(page_list); > >> - int 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_init(&page->lru); > > > > Why change to list_del_init? It's more special than list_del but doesn't seem > > needed since the page is list_add()ed later. > > Not something special is here, I'll remove this _init. > > > That postprocess script from patch 1 seems kinda broken before this series, and > > still is. Not that it should block this change. Out of curiosity did you get > > it to run? > > I fixed all new warnings, which come with my changes, so the patch does not make > the script worse. > > If you change all already existing warnings by renaming variables in appropriate > places, the script will work in some way. But I'm not sure this is enough to get > results correct, and I have no a big wish to dive into perl to fix warnings > introduced by another people, so I don't plan to do with this script something else. Ok, was asking in case I was doing something wrong. With the above change, for the series, you can add Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
On 16.02.2019 01:13, Daniel Jordan wrote: > On Fri, Feb 15, 2019 at 10:01:05PM +0000, Kirill Tkhai wrote: >> On 15.02.2019 23:39, Daniel Jordan wrote: >>> On Thu, Feb 14, 2019 at 01:35:37PM +0300, Kirill Tkhai wrote: >>>> +static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, >>>> + struct list_head *list) >>>> { >>>> struct pglist_data *pgdat = lruvec_pgdat(lruvec); >>>> + int nr_pages, nr_moved = 0; >>>> LIST_HEAD(pages_to_free); >>>> + struct page *page; >>>> + enum lru_list lru; >>>> >>>> - /* >>>> - * Put back any unfreeable pages. >>>> - */ >>>> - while (!list_empty(page_list)) { >>>> - struct page *page = lru_to_page(page_list); >>>> - int 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_init(&page->lru); >>> >>> Why change to list_del_init? It's more special than list_del but doesn't seem >>> needed since the page is list_add()ed later. >> >> Not something special is here, I'll remove this _init. >> >>> That postprocess script from patch 1 seems kinda broken before this series, and >>> still is. Not that it should block this change. Out of curiosity did you get >>> it to run? >> >> I fixed all new warnings, which come with my changes, so the patch does not make >> the script worse. >> >> If you change all already existing warnings by renaming variables in appropriate >> places, the script will work in some way. But I'm not sure this is enough to get >> results correct, and I have no a big wish to dive into perl to fix warnings >> introduced by another people, so I don't plan to do with this script something else. > > Ok, was asking in case I was doing something wrong. > > With the above change, for the series, you can add > > Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Ok, thanks.
diff --git a/mm/vmscan.c b/mm/vmscan.c index 656a9b5af2a4..fcec2385dda2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1807,33 +1807,53 @@ static int too_many_isolated(struct pglist_data *pgdat, int file, return isolated > inactive; } -static noinline_for_stack void -putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list) +/* + * This moves pages from @list to corresponding LRU list. + * + * We move them the other way if the page is referenced by one or more + * processes, from rmap. + * + * If the pages are mostly unmapped, the processing is fast and it is + * appropriate to hold zone_lru_lock across the whole operation. But if + * the pages are mapped, the processing is slow (page_referenced()) so we + * should drop zone_lru_lock around each page. It's impossible to balance + * this, so instead we remove the pages from the LRU while processing them. + * It is safe to rely on PG_active against the non-LRU pages in here because + * nobody will play with that bit on a non-LRU page. + * + * The downside is that we have to touch page->_refcount against each page. + * But we had to alter page->flags anyway. + * + * Returns the number of pages moved to the given lruvec. + */ + +static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, + struct list_head *list) { struct pglist_data *pgdat = lruvec_pgdat(lruvec); + int nr_pages, nr_moved = 0; LIST_HEAD(pages_to_free); + struct page *page; + enum lru_list lru; - /* - * Put back any unfreeable pages. - */ - while (!list_empty(page_list)) { - struct page *page = lru_to_page(page_list); - int 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_init(&page->lru); spin_unlock_irq(&pgdat->lru_lock); putback_lru_page(page); spin_lock_irq(&pgdat->lru_lock); continue; } - lruvec = mem_cgroup_page_lruvec(page, pgdat); SetPageLRU(page); lru = page_lru(page); - add_page_to_lru_list(page, lruvec, lru); + + nr_pages = hpage_nr_pages(page); + update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); + list_move(&page->lru, &lruvec->lists[lru]); if (put_page_testzero(page)) { __ClearPageLRU(page); @@ -1847,13 +1867,17 @@ putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list) spin_lock_irq(&pgdat->lru_lock); } else list_add(&page->lru, &pages_to_free); + } else { + nr_moved += nr_pages; } } /* * To save our caller's stack, now use input list for pages to free. */ - list_splice(&pages_to_free, page_list); + list_splice(&pages_to_free, list); + + return nr_moved; } /* @@ -1945,7 +1969,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, reclaim_stat->recent_rotated[0] = stat.nr_activate[0]; reclaim_stat->recent_rotated[1] = stat.nr_activate[1]; - putback_inactive_pages(lruvec, &page_list); + move_pages_to_lru(lruvec, &page_list); __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken); @@ -1982,72 +2006,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, return nr_reclaimed; } -/* - * This moves pages from the active list to the inactive list. - * - * We move them the other way if the page is referenced by one or more - * processes, from rmap. - * - * If the pages are mostly unmapped, the processing is fast and it is - * appropriate to hold zone_lru_lock across the whole operation. But if - * the pages are mapped, the processing is slow (page_referenced()) so we - * should drop zone_lru_lock around each page. It's impossible to balance - * this, so instead we remove the pages from the LRU while processing them. - * It is safe to rely on PG_active against the non-LRU pages in here because - * nobody will play with that bit on a non-LRU page. - * - * The downside is that we have to touch page->_refcount against each page. - * But we had to alter page->flags anyway. - * - * Returns the number of pages moved to the given lru. - */ - -static unsigned move_active_pages_to_lru(struct lruvec *lruvec, - struct list_head *list, - enum lru_list lru) -{ - struct pglist_data *pgdat = lruvec_pgdat(lruvec); - LIST_HEAD(pages_to_free); - struct page *page; - int nr_pages; - int nr_moved = 0; - - while (!list_empty(list)) { - page = lru_to_page(list); - lruvec = mem_cgroup_page_lruvec(page, pgdat); - - VM_BUG_ON_PAGE(PageLRU(page), page); - SetPageLRU(page); - - nr_pages = hpage_nr_pages(page); - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); - list_move(&page->lru, &lruvec->lists[lru]); - - if (put_page_testzero(page)) { - __ClearPageLRU(page); - __ClearPageActive(page); - del_page_from_lru_list(page, lruvec, lru); - - if (unlikely(PageCompound(page))) { - spin_unlock_irq(&pgdat->lru_lock); - mem_cgroup_uncharge(page); - (*get_compound_page_dtor(page))(page); - spin_lock_irq(&pgdat->lru_lock); - } else - list_add(&page->lru, &pages_to_free); - } else { - nr_moved += nr_pages; - } - } - - /* - * To save our caller's stack, now use input list for pages to free. - */ - list_splice(&pages_to_free, list); - - return nr_moved; -} - static void shrink_active_list(unsigned long nr_to_scan, struct lruvec *lruvec, struct scan_control *sc, @@ -2134,8 +2092,8 @@ static void shrink_active_list(unsigned long nr_to_scan, */ reclaim_stat->recent_rotated[file] += nr_rotated; - nr_activate = move_active_pages_to_lru(lruvec, &l_active, lru); - nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, lru - LRU_ACTIVE); + nr_activate = move_pages_to_lru(lruvec, &l_active); + nr_deactivate = move_pages_to_lru(lruvec, &l_inactive); /* Keep all free pages in l_active list */ list_splice(&l_inactive, &l_active);
This combines two similar functions move_active_pages_to_lru() and putback_inactive_pages() into single move_pages_to_lru(). This remove duplicate code and makes object file size smaller. Before: text data bss dec hex filename 57082 4732 128 61942 f1f6 mm/vmscan.o After: text data bss dec hex filename 55112 4600 128 59840 e9c0 mm/vmscan.o Note, that now we are checking for !page_evictable() coming from shrink_active_list(), which shouldn't change any behavior since that path works with evictable pages only. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> v2: Move VM_BUG_ON() up. --- mm/vmscan.c | 122 +++++++++++++++++++---------------------------------------- 1 file changed, 40 insertions(+), 82 deletions(-)