Message ID | 20210511214735.1836149-8-willy@infradead.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Memory folios | expand |
Nitpick: function names in subject should IMHO also end with (). But not a reason for resend all patches that don't... On 5/11/21 11:47 PM, Matthew Wilcox (Oracle) wrote: > If we know we have a folio, we can call folio_get() instead > of get_page() and save the overhead of calling compound_head(). > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > Reviewed-by: Zi Yan <ziy@nvidia.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > include/linux/mm.h | 26 +++++++++++++++++--------- > 1 file changed, 17 insertions(+), 9 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 610948f0cb43..feb4645ef4f2 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1219,18 +1219,26 @@ static inline bool is_pci_p2pdma_page(const struct page *page) > } > > /* 127: arbitrary random number, small enough to assemble well */ > -#define page_ref_zero_or_close_to_overflow(page) \ > - ((unsigned int) page_ref_count(page) + 127u <= 127u) > +#define folio_ref_zero_or_close_to_overflow(folio) \ > + ((unsigned int) folio_ref_count(folio) + 127u <= 127u) > + > +/** > + * folio_get - Increment the reference count on a folio. > + * @folio: The folio. > + * > + * Context: May be called in any context, as long as you know that > + * you have a refcount on the folio. If you do not already have one, > + * folio_try_get() may be the right interface for you to use. > + */ > +static inline void folio_get(struct folio *folio) > +{ > + VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio); > + folio_ref_inc(folio); > +} > > static inline void get_page(struct page *page) > { > - page = compound_head(page); > - /* > - * Getting a normal page or the head of a compound page > - * requires to already have an elevated page->_refcount. > - */ > - VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page); > - page_ref_inc(page); > + folio_get(page_folio(page)); > } > > bool __must_check try_grab_page(struct page *page, unsigned int flags); >
On Fri, May 14, 2021 at 01:56:46PM +0200, Vlastimil Babka wrote: > Nitpick: function names in subject should IMHO also end with (). But not a > reason for resend all patches that don't... Hm, I thought it was preferred to not do that. I can fix it easily enough when I go through and add the R-b.
On 5/14/21 4:24 PM, Matthew Wilcox wrote: > On Fri, May 14, 2021 at 01:56:46PM +0200, Vlastimil Babka wrote: >> Nitpick: function names in subject should IMHO also end with (). But not a >> reason for resend all patches that don't... > > Hm, I thought it was preferred to not do that. Hm, no idea if there's a concensus on that, actually. > I can fix it > easily enough when I go through and add the R-b. If I was right...
On Fri, May 14, 2021 at 03:24:26PM +0100, Matthew Wilcox wrote: > On Fri, May 14, 2021 at 01:56:46PM +0200, Vlastimil Babka wrote: > > Nitpick: function names in subject should IMHO also end with (). But not a > > reason for resend all patches that don't... > > Hm, I thought it was preferred to not do that. I can fix it > easily enough when I go through and add the R-b. I hate the pointless (). Some maintainers insist on it. No matter what you do you'll make some folks happy and others not.
On Thu, 27 May 2021 09:10:31 +0100 Christoph Hellwig <hch@infradead.org> wrote: > On Fri, May 14, 2021 at 03:24:26PM +0100, Matthew Wilcox wrote: > > On Fri, May 14, 2021 at 01:56:46PM +0200, Vlastimil Babka wrote: > > > Nitpick: function names in subject should IMHO also end with (). But not a > > > reason for resend all patches that don't... > > > > Hm, I thought it was preferred to not do that. I can fix it > > easily enough when I go through and add the R-b. > > I hate the pointless (). Some maintainers insist on it. No matter > what you do you'll make some folks happy and others not. I prefer it. It succinctly says "this identifier is a function" which is useful info. I get many changelogs saying "the foo function" or "the function foo". "foo()" is better.
diff --git a/include/linux/mm.h b/include/linux/mm.h index 610948f0cb43..feb4645ef4f2 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1219,18 +1219,26 @@ static inline bool is_pci_p2pdma_page(const struct page *page) } /* 127: arbitrary random number, small enough to assemble well */ -#define page_ref_zero_or_close_to_overflow(page) \ - ((unsigned int) page_ref_count(page) + 127u <= 127u) +#define folio_ref_zero_or_close_to_overflow(folio) \ + ((unsigned int) folio_ref_count(folio) + 127u <= 127u) + +/** + * folio_get - Increment the reference count on a folio. + * @folio: The folio. + * + * Context: May be called in any context, as long as you know that + * you have a refcount on the folio. If you do not already have one, + * folio_try_get() may be the right interface for you to use. + */ +static inline void folio_get(struct folio *folio) +{ + VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio); + folio_ref_inc(folio); +} static inline void get_page(struct page *page) { - page = compound_head(page); - /* - * Getting a normal page or the head of a compound page - * requires to already have an elevated page->_refcount. - */ - VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page); - page_ref_inc(page); + folio_get(page_folio(page)); } bool __must_check try_grab_page(struct page *page, unsigned int flags);