Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760197AbbLCNqQ (ORCPT ); Thu, 3 Dec 2015 08:46:16 -0500 Received: from mx2.suse.de ([195.135.220.15]:58400 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752542AbbLCNqO (ORCPT ); Thu, 3 Dec 2015 08:46:14 -0500 Subject: Re: [PATCH 1/2] mm, printk: introduce new format string for flags To: Rasmus Villemoes References: <20151125143010.GI27283@dhcp22.suse.cz> <1448899821-9671-1-git-send-email-vbabka@suse.cz> <87io4hi06n.fsf@rasmusvillemoes.dk> <565F55E6.6080201@suse.cz> <87mvtrpv1o.fsf@rasmusvillemoes.dk> Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Joonsoo Kim , Minchan Kim , Sasha Levin , "Kirill A. Shutemov" , Mel Gorman , Michal Hocko From: Vlastimil Babka Message-ID: <566047A2.2050701@suse.cz> Date: Thu, 3 Dec 2015 14:46:10 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <87mvtrpv1o.fsf@rasmusvillemoes.dk> Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2562 Lines: 65 On 12/03/2015 01:37 PM, Rasmus Villemoes wrote: > On Wed, Dec 02 2015, Vlastimil Babka wrote: >> --- a/include/linux/mmdebug.h >> +++ b/include/linux/mmdebug.h >> @@ -7,6 +7,9 @@ >> struct page; >> struct vm_area_struct; >> struct mm_struct; >> +struct trace_print_flags; // can't include trace_events.h here >> + >> +extern const struct trace_print_flags *pageflag_names; >> >> extern void dump_page(struct page *page, const char *reason); >> extern void dump_page_badflags(struct page *page, const char *reason, >> diff --git a/mm/debug.c b/mm/debug.c >> index a092111920e7..1cbc60544b87 100644 >> --- a/mm/debug.c >> +++ b/mm/debug.c >> @@ -23,7 +23,7 @@ char *migrate_reason_names[MR_TYPES] = { >> "cma", >> }; >> >> -static const struct trace_print_flags pageflag_names[] = { >> +const struct trace_print_flags __pageflag_names[] = { >> {1UL << PG_locked, "locked" }, >> {1UL << PG_error, "error" }, >> {1UL << PG_referenced, "referenced" }, >> @@ -59,6 +59,8 @@ static const struct trace_print_flags pageflag_names[] = { >> #endif >> }; >> >> +const struct trace_print_flags *pageflag_names = &__pageflag_names[0]; > > Ugh. I think it would be better if either the definition of struct > trace_print_flags is moved somewhere where everybody can see it or to > make our own identical type definition. For now I'd go with the latter, > also since this doesn't really have anything to do with the tracing > subsystem. Then just declare the array in the header > > extern const struct print_flags pageflag_names[]; Ugh so yesterday I copy/pasted the definition and still got an error, which I probably didn't read closely enough. I assumed that if it needs the full definition of "struct trace_print_flags" here to know the size, it would also need to know the lenght of the array as well. But now it works. Well, copy/pasting the definition fails as long as both headers are included and it's redefining the struct (even though it's the same thing). But looks like I can move it from trace_events.h to tracepoint.h and it won't blow off (knock knock). I suck at C. > (If you do the extra indirection thing, __pageflag_names could still be > static, and it would be best to declare the pointer itself const as > well, but I'd rather we don't go that way.) > > Rasmus > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/