linux-kernel - Re: [PATCH RFC v3 04/35] mm: page_alloc: Partially revert "mm: page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 29 Jan 2024 11:46:12 +0000
From: Alexandru Elisei <alexandru.elisei@....com>
To: Anshuman Khandual <anshuman.khandual@....com>
Cc: catalin.marinas@....com, will@...nel.org, oliver.upton@...ux.dev,
	maz@...nel.org, james.morse@....com, suzuki.poulose@....com,
	yuzenghui@...wei.com, arnd@...db.de, akpm@...ux-foundation.org,
	mingo@...hat.com, peterz@...radead.org, juri.lelli@...hat.com,
	vincent.guittot@...aro.org, dietmar.eggemann@....com,
	rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
	bristot@...hat.com, vschneid@...hat.com, mhiramat@...nel.org,
	rppt@...nel.org, hughd@...gle.com, pcc@...gle.com,
	steven.price@....com, vincenzo.frascino@....com, david@...hat.com,
	eugenis@...gle.com, kcc@...gle.com, hyesoo.yu@...sung.com,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	kvmarm@...ts.linux.dev, linux-fsdevel@...r.kernel.org,
	linux-arch@...r.kernel.org, linux-mm@...ck.org,
	linux-trace-kernel@...r.kernel.org
Subject: Re: [PATCH RFC v3 04/35] mm: page_alloc: Partially revert "mm:
 page_alloc: remove stale CMA guard code"

Hi,

On Mon, Jan 29, 2024 at 02:31:23PM +0530, Anshuman Khandual wrote:
> 
> 
> On 1/25/24 22:12, Alexandru Elisei wrote:
> > The patch f945116e4e19 ("mm: page_alloc: remove stale CMA guard code")
> > removed the CMA filter when allocating from the MIGRATE_MOVABLE pcp list
> > because CMA is always allowed when __GFP_MOVABLE is set.
> > 
> > With the introduction of the arch_alloc_cma() function, the above is not
> > true anymore, so bring back the filter.
> 
> This makes sense as arch_alloc_cma() now might prevent ALLOC_CMA being
> assigned to alloc_flags in gfp_to_alloc_flags_cma().

Can I add your Reviewed-by tag then?

Thanks,
Alex

> 
> > 
> > This is a partially revert because the stale comment remains removed.
> > 
> > Signed-off-by: Alexandru Elisei <alexandru.elisei@....com>
> > ---
> >  mm/page_alloc.c | 15 +++++++++++----
> >  1 file changed, 11 insertions(+), 4 deletions(-)
> > 
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index a96d47a6393e..0fa34bcfb1af 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -2897,10 +2897,17 @@ struct page *rmqueue(struct zone *preferred_zone,
> >  	WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
> >  
> >  	if (likely(pcp_allowed_order(order))) {
> > -		page = rmqueue_pcplist(preferred_zone, zone, order,
> > -				       migratetype, alloc_flags);
> > -		if (likely(page))
> > -			goto out;
> > +		/*
> > +		 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
> > +		 * we need to skip it when CMA area isn't allowed.
> > +		 */
> > +		if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA ||
> > +				migratetype != MIGRATE_MOVABLE) {
> > +			page = rmqueue_pcplist(preferred_zone, zone, order,
> > +					migratetype, alloc_flags);
> > +			if (likely(page))
> > +				goto out;
> > +		}
> >  	}
> >  
> >  	page = rmqueue_buddy(preferred_zone, zone, order, alloc_flags,