| Message ID | 1403025266-2326-1-git-send-email-msalter@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jun 17, 2014 at 06:14:26PM +0100, Mark Salter wrote: > The __cpu_clear_user_page() and __cpu_copy_user_page() functions > are not currently exported. This prevents modules from using > clear_user_page() and opy_user_page(). > > Signed-off-by: Mark Salter <msalter@redhat.com> > --- > arch/arm64/mm/copypage.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c > index 9aecbac..13bbc3be 100644 > --- a/arch/arm64/mm/copypage.c > +++ b/arch/arm64/mm/copypage.c > @@ -27,8 +27,10 @@ void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr) > copy_page(kto, kfrom); > __flush_dcache_area(kto, PAGE_SIZE); > } > +EXPORT_SYMBOL_GPL(__cpu_copy_user_page); > > void __cpu_clear_user_page(void *kaddr, unsigned long vaddr) > { > clear_page(kaddr); > } > +EXPORT_SYMBOL_GPL(__cpu_clear_user_page); I wonder why we still have these functions. I don't think we need any D-cache flushing for copy_user_page(), so we could simply remove this code and define copy_user_page() as copy_page() (similarly for clear_user_page). I'll post a patch separately removing the copy_page, copy_user_page etc. functions (now that we also have optimised memcpy and memset).
On Wed, 2014-06-18 at 11:39 +0100, Catalin Marinas wrote: > On Tue, Jun 17, 2014 at 06:14:26PM +0100, Mark Salter wrote: > > The __cpu_clear_user_page() and __cpu_copy_user_page() functions > > are not currently exported. This prevents modules from using > > clear_user_page() and opy_user_page(). > > > > Signed-off-by: Mark Salter <msalter@redhat.com> > > --- > > arch/arm64/mm/copypage.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c > > index 9aecbac..13bbc3be 100644 > > --- a/arch/arm64/mm/copypage.c > > +++ b/arch/arm64/mm/copypage.c > > @@ -27,8 +27,10 @@ void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr) > > copy_page(kto, kfrom); > > __flush_dcache_area(kto, PAGE_SIZE); > > } > > +EXPORT_SYMBOL_GPL(__cpu_copy_user_page); > > > > void __cpu_clear_user_page(void *kaddr, unsigned long vaddr) > > { > > clear_page(kaddr); > > } > > +EXPORT_SYMBOL_GPL(__cpu_clear_user_page); > > I wonder why we still have these functions. I don't think we need any > D-cache flushing for copy_user_page(), so we could simply remove this > code and define copy_user_page() as copy_page() (similarly for > clear_user_page). I'll post a patch separately removing the copy_page, > copy_user_page etc. functions (now that we also have optimised memcpy > and memset). > Even better. I much prefer removing code than adding it. Thanks.
On Wed, Jun 18, 2014 at 02:54:03PM +0100, Mark Salter wrote: > On Wed, 2014-06-18 at 11:39 +0100, Catalin Marinas wrote: > > On Tue, Jun 17, 2014 at 06:14:26PM +0100, Mark Salter wrote: > > > The __cpu_clear_user_page() and __cpu_copy_user_page() functions > > > are not currently exported. This prevents modules from using > > > clear_user_page() and opy_user_page(). > > > > > > Signed-off-by: Mark Salter <msalter@redhat.com> > > > --- > > > arch/arm64/mm/copypage.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c > > > index 9aecbac..13bbc3be 100644 > > > --- a/arch/arm64/mm/copypage.c > > > +++ b/arch/arm64/mm/copypage.c > > > @@ -27,8 +27,10 @@ void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr) > > > copy_page(kto, kfrom); > > > __flush_dcache_area(kto, PAGE_SIZE); > > > } > > > +EXPORT_SYMBOL_GPL(__cpu_copy_user_page); > > > > > > void __cpu_clear_user_page(void *kaddr, unsigned long vaddr) > > > { > > > clear_page(kaddr); > > > } > > > +EXPORT_SYMBOL_GPL(__cpu_clear_user_page); > > > > I wonder why we still have these functions. I don't think we need any > > D-cache flushing for copy_user_page(), so we could simply remove this > > code and define copy_user_page() as copy_page() (similarly for > > clear_user_page). I'll post a patch separately removing the copy_page, > > copy_user_page etc. functions (now that we also have optimised memcpy > > and memset). > > Even better. I much prefer removing code than adding it. Thanks. For the time being I'll merge your patch since using memset for clear_page adds a small overhead with checking the alignment and the fill value (not much but consistently slower in my mmap benchmarks).
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c index 9aecbac..13bbc3be 100644 --- a/arch/arm64/mm/copypage.c +++ b/arch/arm64/mm/copypage.c @@ -27,8 +27,10 @@ void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr) copy_page(kto, kfrom); __flush_dcache_area(kto, PAGE_SIZE); } +EXPORT_SYMBOL_GPL(__cpu_copy_user_page); void __cpu_clear_user_page(void *kaddr, unsigned long vaddr) { clear_page(kaddr); } +EXPORT_SYMBOL_GPL(__cpu_clear_user_page);
The __cpu_clear_user_page() and __cpu_copy_user_page() functions are not currently exported. This prevents modules from using clear_user_page() and opy_user_page(). Signed-off-by: Mark Salter <msalter@redhat.com> --- arch/arm64/mm/copypage.c | 2 ++ 1 file changed, 2 insertions(+)