Re: [PATCH 2/5] test_printf: Assign all flags to page_flags

[Petr Mladek <pmladek@suse.com>]

On Wed 2021-10-13 12:25:30, Kirill A. Shutemov wrote:
> On Tue, Oct 12, 2021 at 07:26:44PM +0100, Matthew Wilcox (Oracle) wrote:
> > Even unknown flags should be passed to %pGp so that we can test what it
> > does with them (today: nothing).
> > 
> > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> > ---
> >  lib/test_printf.c | 6 ++----
> >  1 file changed, 2 insertions(+), 4 deletions(-)
> > 
> > diff --git a/lib/test_printf.c b/lib/test_printf.c
> > index a52c1c3a55ba..f744b0498672 100644
> > --- a/lib/test_printf.c
> > +++ b/lib/test_printf.c
> > @@ -608,14 +608,12 @@ page_flags_test(int section, int node, int zone, int last_cpupid,
> >  		int kasan_tag, int flags, const char *name, char *cmp_buf)
> >  {
> >  	unsigned long values[] = {section, node, zone, last_cpupid, kasan_tag};
> > -	unsigned long page_flags = 0;
> > +	unsigned long page_flags = flags;
> >  	unsigned long size = 0;
> >  	bool append = false;
> >  	int i;
> >  
> > -	flags &= PAGEFLAGS_MASK;
> > -	if (flags) {
> > -		page_flags |= flags;
> > +	if (flags & PAGEFLAGS_MASK) {
> >  		snprintf(cmp_buf + size, BUF_SIZE - size, "%s", name);
> >  		size = strlen(cmp_buf);
> >  #if SECTIONS_WIDTH || NODES_WIDTH || ZONES_WIDTH || \
> 
> Do we even need 'page_flags'? Can't we do everything on 'flags' directly?

I have to say that the meaning of "flags" and "page_flags" variable
is far from clear [*] It would be worth documentation how they are
supposed to be used.

I am going to comment more on this in the 5th patch.

Best Regards,
Petr

[*] Shame on me. I did not pay much attention to the test code
    when reviewing the original code.