| Message ID | 20240409092826.1733637-2-alexs@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | transfer page to folio in KSM | expand |
On 09.04.24 11:28, alexs@kernel.org wrote: > From: "Alex Shi (tencent)" <alexs@kernel.org> > > The ksm only contains single pages, so we could add a new func > ksm_get_folio for get_ksm_page to use folio instead of pages to save a > couple of compound_head calls. > > After all caller replaced, get_ksm_page will be removed. > > Signed-off-by: Alex Shi (tencent) <alexs@kernel.org> > To: Andrew Morton <akpm@linux-foundation.org> > Cc: Izik Eidus <izik.eidus@ravellosystems.com> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: Hugh Dickins <hughd@google.com> > Cc: Chris Wright <chrisw@sous-sol.org> > Reviewed-by: David Hildenbrand <david@redhat.com> Note that the more common way is to have RBs ets fist. Further, I haven't really seen "To:" that often :)
On 4/9/24 6:50 PM, David Hildenbrand wrote: > On 09.04.24 11:28, alexs@kernel.org wrote: >> From: "Alex Shi (tencent)" <alexs@kernel.org> >> >> The ksm only contains single pages, so we could add a new func >> ksm_get_folio for get_ksm_page to use folio instead of pages to save a >> couple of compound_head calls. >> >> After all caller replaced, get_ksm_page will be removed. >> >> Signed-off-by: Alex Shi (tencent) <alexs@kernel.org> >> To: Andrew Morton <akpm@linux-foundation.org> >> Cc: Izik Eidus <izik.eidus@ravellosystems.com> >> Cc: Matthew Wilcox <willy@infradead.org> >> Cc: Andrea Arcangeli <aarcange@redhat.com> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Chris Wright <chrisw@sous-sol.org> >> Reviewed-by: David Hildenbrand <david@redhat.com> > > Note that the more common way is to have RBs ets fist. Further, I haven't really seen "To:" that often :) Hi David, Thanks a lot for notice, will change it in next version. >
On 09.04.24 11:28, alexs@kernel.org wrote: > From: "Alex Shi (tencent)" <alexs@kernel.org> > > The ksm only contains single pages, so we could add a new func > ksm_get_folio for get_ksm_page to use folio instead of pages to save a > couple of compound_head calls. > > After all caller replaced, get_ksm_page will be removed. > > Signed-off-by: Alex Shi (tencent) <alexs@kernel.org> > To: Andrew Morton <akpm@linux-foundation.org> > Cc: Izik Eidus <izik.eidus@ravellosystems.com> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: Hugh Dickins <hughd@google.com> > Cc: Chris Wright <chrisw@sous-sol.org> > Reviewed-by: David Hildenbrand <david@redhat.com> > --- > mm/ksm.c | 40 ++++++++++++++++++++++++---------------- > 1 file changed, 24 insertions(+), 16 deletions(-) > > diff --git a/mm/ksm.c b/mm/ksm.c > index 8c001819cf10..ac080235b002 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -915,10 +915,10 @@ enum get_ksm_page_flags { > * a page to put something that might look like our key in page->mapping. > * is on its way to being freed; but it is an anomaly to bear in mind. > */ > -static struct page *get_ksm_page(struct ksm_stable_node *stable_node, > +static struct folio *ksm_get_folio(struct ksm_stable_node *stable_node, Just realized that you should adjust the function name in the comment above this function in this patch.
On 4/10/24 4:34 PM, David Hildenbrand wrote: > On 09.04.24 11:28, alexs@kernel.org wrote: >> From: "Alex Shi (tencent)" <alexs@kernel.org> >> >> The ksm only contains single pages, so we could add a new func >> ksm_get_folio for get_ksm_page to use folio instead of pages to save a >> couple of compound_head calls. >> >> After all caller replaced, get_ksm_page will be removed. >> >> Signed-off-by: Alex Shi (tencent) <alexs@kernel.org> >> To: Andrew Morton <akpm@linux-foundation.org> >> Cc: Izik Eidus <izik.eidus@ravellosystems.com> >> Cc: Matthew Wilcox <willy@infradead.org> >> Cc: Andrea Arcangeli <aarcange@redhat.com> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Chris Wright <chrisw@sous-sol.org> >> Reviewed-by: David Hildenbrand <david@redhat.com> >> --- >> mm/ksm.c | 40 ++++++++++++++++++++++++---------------- >> 1 file changed, 24 insertions(+), 16 deletions(-) >> >> diff --git a/mm/ksm.c b/mm/ksm.c >> index 8c001819cf10..ac080235b002 100644 >> --- a/mm/ksm.c >> +++ b/mm/ksm.c >> @@ -915,10 +915,10 @@ enum get_ksm_page_flags { >> * a page to put something that might look like our key in page->mapping. >> * is on its way to being freed; but it is an anomaly to bear in mind. >> */ >> -static struct page *get_ksm_page(struct ksm_stable_node *stable_node, >> +static struct folio *ksm_get_folio(struct ksm_stable_node *stable_node, > > Just realized that you should adjust the function name in the comment above this function in this patch. > Right, will resend with your suggestion.
diff --git a/mm/ksm.c b/mm/ksm.c index 8c001819cf10..ac080235b002 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -915,10 +915,10 @@ enum get_ksm_page_flags { * a page to put something that might look like our key in page->mapping. * is on its way to being freed; but it is an anomaly to bear in mind. */ -static struct page *get_ksm_page(struct ksm_stable_node *stable_node, +static struct folio *ksm_get_folio(struct ksm_stable_node *stable_node, enum get_ksm_page_flags flags) { - struct page *page; + struct folio *folio; void *expected_mapping; unsigned long kpfn; @@ -926,8 +926,8 @@ static struct page *get_ksm_page(struct ksm_stable_node *stable_node, PAGE_MAPPING_KSM); again: kpfn = READ_ONCE(stable_node->kpfn); /* Address dependency. */ - page = pfn_to_page(kpfn); - if (READ_ONCE(page->mapping) != expected_mapping) + folio = pfn_folio(kpfn); + if (READ_ONCE(folio->mapping) != expected_mapping) goto stale; /* @@ -940,41 +940,41 @@ static struct page *get_ksm_page(struct ksm_stable_node *stable_node, * in folio_migrate_mapping(), it might still be our page, * in which case it's essential to keep the node. */ - while (!get_page_unless_zero(page)) { + while (!folio_try_get(folio)) { /* * Another check for page->mapping != expected_mapping would * work here too. We have chosen the !PageSwapCache test to * optimize the common case, when the page is or is about to * be freed: PageSwapCache is cleared (under spin_lock_irq) * in the ref_freeze section of __remove_mapping(); but Anon - * page->mapping reset to NULL later, in free_pages_prepare(). + * folio->mapping reset to NULL later, in free_pages_prepare(). */ - if (!PageSwapCache(page)) + if (!folio_test_swapcache(folio)) goto stale; cpu_relax(); } - if (READ_ONCE(page->mapping) != expected_mapping) { - put_page(page); + if (READ_ONCE(folio->mapping) != expected_mapping) { + folio_put(folio); goto stale; } if (flags == GET_KSM_PAGE_TRYLOCK) { - if (!trylock_page(page)) { - put_page(page); + if (!folio_trylock(folio)) { + folio_put(folio); return ERR_PTR(-EBUSY); } } else if (flags == GET_KSM_PAGE_LOCK) - lock_page(page); + folio_lock(folio); if (flags != GET_KSM_PAGE_NOLOCK) { - if (READ_ONCE(page->mapping) != expected_mapping) { - unlock_page(page); - put_page(page); + if (READ_ONCE(folio->mapping) != expected_mapping) { + folio_unlock(folio); + folio_put(folio); goto stale; } } - return page; + return folio; stale: /* @@ -990,6 +990,14 @@ static struct page *get_ksm_page(struct ksm_stable_node *stable_node, return NULL; } +static struct page *get_ksm_page(struct ksm_stable_node *stable_node, + enum get_ksm_page_flags flags) +{ + struct folio *folio = ksm_get_folio(stable_node, flags); + + return &folio->page; +} + /* * Removing rmap_item from stable or unstable tree. * This function will clean the information from the stable/unstable tree.