From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx195.postini.com [74.125.245.195]) by kanga.kvack.org (Postfix) with SMTP id 8195F6B0089 for ; Thu, 29 Dec 2011 06:08:52 -0500 (EST) Date: Thu, 29 Dec 2011 13:08:50 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH] Makefiles: Disable unused-variable warning (was: Re: [PATCH 1/6] memcg: fix unused variable warning) Message-ID: <20111229110850.GA5680@shutemov.name> References: <1324695619-5537-1-git-send-email-kirill@shutemov.name> <20111227135752.GK5344@tiehlicka.suse.cz> <20111227182613.GA21840@shutemov.name> <20111229104230.GA20854@tiehlicka.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <20111229104230.GA20854@tiehlicka.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, KAMEZAWA Hiroyuki , Balbir Singh , Johannes Weiner , Michal Marek , linux-kbuild@vger.kernel.org On Thu, Dec 29, 2011 at 11:42:30AM +0100, Michal Hocko wrote: > On Tue 27-12-11 20:26:13, Kirill A. Shutemov wrote: > > On Tue, Dec 27, 2011 at 02:57:52PM +0100, Michal Hocko wrote: > > > On Sat 24-12-11 05:00:14, Kirill A. Shutemov wrote: > > > > From: "Kirill A. Shutemov" > > > >=20 > > > > mm/memcontrol.c: In function =E2=80=98memcg_check_events=E2=80=99: > > > > mm/memcontrol.c:784:22: warning: unused variable =E2=80=98do_numain= fo=E2=80=99 [-Wunused-variable] > > > >=20 > > > > Signed-off-by: Kirill A. Shutemov > > > > --- > > > > mm/memcontrol.c | 7 ++++--- > > > > 1 files changed, 4 insertions(+), 3 deletions(-) > > > >=20 > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > > > index d643bd6..a5e92bd 100644 > > > > --- a/mm/memcontrol.c > > > > +++ b/mm/memcontrol.c > > > > @@ -781,14 +781,15 @@ static void memcg_check_events(struct mem_cgr= oup *memcg, struct page *page) > > > > /* threshold event is triggered in finer grain than soft limit */ > > > > if (unlikely(mem_cgroup_event_ratelimit(memcg, > > > > MEM_CGROUP_TARGET_THRESH))) { > > > > - bool do_softlimit, do_numainfo; > > > > + bool do_softlimit; > > > > =20 > > > > - do_softlimit =3D mem_cgroup_event_ratelimit(memcg, > > > > - MEM_CGROUP_TARGET_SOFTLIMIT); > > > > #if MAX_NUMNODES > 1 > > > > + bool do_numainfo; > > > > do_numainfo =3D mem_cgroup_event_ratelimit(memcg, > > > > MEM_CGROUP_TARGET_NUMAINFO); > > > > #endif > > > > + do_softlimit =3D mem_cgroup_event_ratelimit(memcg, > > > > + MEM_CGROUP_TARGET_SOFTLIMIT); > > >=20 > > > I don't like this very much. Maybe we should get rid of both do_* and > > > do it with flags? But maybe it is not worth the additional code at > > > all... > >=20 > > Something like this (untested): > > =3D=3D=3D=3D > > From f57e1a2e1aaaa167c75b963d5bf12fcbdd3331b8 Mon Sep 17 00:00:00 2001 > > From: "Kirill A. Shutemov" > > Date: Tue, 27 Dec 2011 20:17:13 +0200 > > Subject: [PATCH] memcg: cleanup memcg_check_events() > >=20 > > Signed-off-by: Kirill A. Shutemov >=20 > The patch looks correct but I am still not sure this is worth fixing in > the code rather than disabling Wunused-variable. Does it look better then original code from your POV? It's a bit cleaner, I think. >=20 > > --- > > mm/memcontrol.c | 42 ++++++++++++++++++++++++------------------ > > 1 files changed, 24 insertions(+), 18 deletions(-) > >=20 > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index d643bd6..40c2236 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -108,11 +108,12 @@ enum mem_cgroup_events_index { > > * than using jiffies etc. to handle periodic memcg event. > > */ > > enum mem_cgroup_events_target { > > - MEM_CGROUP_TARGET_THRESH, > > - MEM_CGROUP_TARGET_SOFTLIMIT, > > - MEM_CGROUP_TARGET_NUMAINFO, > > - MEM_CGROUP_NTARGETS, > > + MEM_CGROUP_TARGET_THRESH =3D BIT(1), > > + MEM_CGROUP_TARGET_SOFTLIMIT =3D BIT(2), > > + MEM_CGROUP_TARGET_NUMAINFO =3D BIT(3), > > }; > > +#define MEM_CGROUP_NTARGETS 3 > > + > > #define THRESHOLDS_EVENTS_TARGET (128) > > #define SOFTLIMIT_EVENTS_TARGET (1024) > > #define NUMAINFO_EVENTS_TARGET (1024) > > @@ -743,7 +744,7 @@ static unsigned long mem_cgroup_nr_lru_pages(struct= mem_cgroup *memcg, > > return total; > > } > > =20 > > -static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, > > +static int mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, > > enum mem_cgroup_events_target target) > > { > > unsigned long val, next; > > @@ -766,9 +767,9 @@ static bool mem_cgroup_event_ratelimit(struct mem_c= group *memcg, > > break; > > } > > __this_cpu_write(memcg->stat->targets[target], next); > > - return true; > > + return target; > > } > > - return false; > > + return 0; > > } > > =20 > > /* > > @@ -777,29 +778,34 @@ static bool mem_cgroup_event_ratelimit(struct mem= _cgroup *memcg, > > */ > > static void memcg_check_events(struct mem_cgroup *memcg, struct page *= page) > > { > > + int flags; > > + > > preempt_disable(); > > - /* threshold event is triggered in finer grain than soft limit */ > > - if (unlikely(mem_cgroup_event_ratelimit(memcg, > > - MEM_CGROUP_TARGET_THRESH))) { > > - bool do_softlimit, do_numainfo; > > + flags =3D mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_THRESH); > > =20 > > - do_softlimit =3D mem_cgroup_event_ratelimit(memcg, > > + /* > > + * Threshold event is triggered in finer grain than soft limit > > + * and numainfo > > + */ > > + if (unlikely(flags)) { > > + flags |=3D mem_cgroup_event_ratelimit(memcg, > > MEM_CGROUP_TARGET_SOFTLIMIT); > > #if MAX_NUMNODES > 1 > > - do_numainfo =3D mem_cgroup_event_ratelimit(memcg, > > + flags |=3D mem_cgroup_event_ratelimit(memcg, > > MEM_CGROUP_TARGET_NUMAINFO); > > #endif > > - preempt_enable(); > > + } > > + preempt_enable(); > > =20 > > + if (unlikely(flags)) { > > mem_cgroup_threshold(memcg); > > - if (unlikely(do_softlimit)) > > + if (unlikely(flags & MEM_CGROUP_TARGET_SOFTLIMIT)) > > mem_cgroup_update_tree(memcg, page); > > #if MAX_NUMNODES > 1 > > - if (unlikely(do_numainfo)) > > + if (unlikely(flags & MEM_CGROUP_TARGET_NUMAINFO)) > > atomic_inc(&memcg->numainfo_events); > > #endif > > - } else > > - preempt_enable(); > > + } > > } > > =20 > > struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) > > --=20 > > 1.7.7.3 >=20 > --=20 > Michal Hocko > SUSE Labs > SUSE LINUX s.r.o. > Lihovarska 1060/12 > 190 00 Praha 9 =20 > Czech Republic --=20 Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org