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charset=us-ascii Content-Disposition: inline In-Reply-To: <99073d55-5b18-4ed2-b860-8c09e056f585@redhat.com> User-Agent: NeoMutt/20170113 (1.7.2) X-Rspam-User: X-Rspamd-Queue-Id: 9B93A1A0005 X-Rspamd-Server: rspam01 X-Stat-Signature: y7aqfs3yzrnj6jxmkzqoz9u8jxqob1hu X-HE-Tag: 1718067399-925198 X-HE-Meta: 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 IMxplr6/ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jun 10, 2024 at 10:22:49AM +0200, David Hildenbrand wrote: >On 10.06.24 05:40, Oscar Salvador wrote: >> On Fri, Jun 07, 2024 at 10:37:11AM +0200, David Hildenbrand wrote: >> > It looks rather weird that totalhigh_pages() returns an >> > "unsigned long" but nr_free_highpages() returns an "unsigned int". >> > >> > Let's return an "unsigned long" from nr_free_highpages() to be >> > consistent. >> > >> > While at it, use a plain "0" instead of a "0UL" in the !CONFIG_HIGHMEM >> > totalhigh_pages() implementation, to make these look alike as well. >> > >> > Signed-off-by: David Hildenbrand >> ... >> > -static inline unsigned int nr_free_highpages(void) { return 0; } >> > -static inline unsigned long totalhigh_pages(void) { return 0UL; } >> > +static inline unsigned long nr_free_highpages(void) { return 0; } >> > +static inline unsigned long totalhigh_pages(void) { return 0; } >> >> Although I doubt it has any consequences, I would just leave them both with UL, >> so the return type is consistent with what we are returning. > >These suffixes are only required when using constants that would not fit >into the native (int) type, or converting from that native (int) type to >something else automatically by the compiler would mess things up (for example, >undesired sign extension). For 0 that is certainly impossible :) > > >That's also the reason why in include/linux we now have: > >t14s: ~/git/linux/include/linux $ git grep "return 0UL;" >skbuff.h: return 0UL; >uaccess.h:static inline unsigned long user_access_save(void) { return 0UL; } >t14s: ~/git/linux/include/linux $ git grep "0UL;" >bitmap.h: *dst = ~0UL; >dax.h: return ~0UL; >mtd/map.h: r.x[i] = ~0UL; >netfilter.h: return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL; >skbuff.h: return 0UL; >uaccess.h:static inline unsigned long user_access_save(void) { return 0UL; } > > >... compared to a long list if "unsigned long" functions that simply "return 0;" > Seems this is the current status. Then my question is do we have a guide line for this? Or 0 is the special case? Sounds positive value has no sign extension problem. If we need to return 1, we suppose to use 1 or 1UL? I found myself confused. I grepped "return 1" and do find some cases without UL: backing-dev.h: wb_stat_error() return 1 for unsigned long. pgtable.h: pte_batch_hint() return 1 for unsigned int. So the guide line is for positive value, it is not necessary to use UL? > >So I prefer to just drop it. > >Thanks! > >-- >Cheers, > >David / dhildenb -- Wei Yang Help you, Help me