From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: Re: [PATCH 7/8] mm: vmscan: split shrink_node() into node part and memcgs part Date: Tue, 22 Oct 2019 20:08:23 +0000 Message-ID: <20191022200819.GC22721@tower.DHCP.thefacebook.com> References: <20191022144803.302233-1-hannes@cmpxchg.org> <20191022144803.302233-8-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=kSxBKKs/CV01OvG76EJpyOie2QydFm1ggqmmSisDNmE=; b=i2nm7uUuJNSa9jAWC6h8Wqlep677YI2WZ/GblPvUPBYNuupvIhtJrptFE0tTL+KmU4YC woW5ru/6S84q+iXUwTczu1jpnm1K6Gn13cCUOf2kJacT/pvcl2EoXVqa7EmdYZW/jO1W vI3kJBXWHdJI8+Gs+QuEB1FGCXT/0VkYnlU= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector2-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=kSxBKKs/CV01OvG76EJpyOie2QydFm1ggqmmSisDNmE=; b=dVjJVN7U0vFlO5PfQTcR/aXQvtWG5MeK1sIvtcPZPLaYdeFpbjSsO+SBr5G83z4B0sIFf1WvTxNquWDFIq99UGi3rtmmlcIwb4c26vP8tPfI5S9RtR1FSYThj0S8INP4YGRITL0kjjzu2mdg98CKASsrlgKKROKAUKss13cwt0Y= In-Reply-To: <20191022144803.302233-8-hannes@cmpxchg.org> Content-Language: en-US Content-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , "linux-mm@kvack.org" , "cgroups@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Kernel Team On Tue, Oct 22, 2019 at 10:48:02AM -0400, Johannes Weiner wrote: > This function is getting long and unwieldy, split out the memcg bits. >=20 > The updated shrink_node() handles the generic (node) reclaim aspects: > - global vmpressure notifications > - writeback and congestion throttling > - reclaim/compaction management > - kswapd giving up on unreclaimable nodes >=20 > It then calls a new shrink_node_memcgs() which handles cgroup specifics: > - the cgroup tree traversal > - memory.low considerations > - per-cgroup slab shrinking callbacks > - per-cgroup vmpressure notifications >=20 > Signed-off-by: Johannes Weiner > --- > mm/vmscan.c | 28 ++++++++++++++++++---------- > 1 file changed, 18 insertions(+), 10 deletions(-) >=20 > diff --git a/mm/vmscan.c b/mm/vmscan.c > index db073b40c432..65baa89740dd 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2722,18 +2722,10 @@ static bool pgdat_memcg_congested(pg_data_t *pgda= t, struct mem_cgroup *memcg) > (memcg && memcg_congested(pgdat, memcg)); > } > =20 > -static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) > +static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc= ) > { > - struct reclaim_state *reclaim_state =3D current->reclaim_state; > struct mem_cgroup *root =3D sc->target_mem_cgroup; > - unsigned long nr_reclaimed, nr_scanned; > - bool reclaimable =3D false; > struct mem_cgroup *memcg; > -again: > - memset(&sc->nr, 0, sizeof(sc->nr)); > - > - nr_reclaimed =3D sc->nr_reclaimed; > - nr_scanned =3D sc->nr_scanned; > =20 > memcg =3D mem_cgroup_iter(root, NULL, NULL); > do { > @@ -2786,6 +2778,22 @@ static bool shrink_node(pg_data_t *pgdat, struct s= can_control *sc) > sc->nr_reclaimed - reclaimed); > =20 > } while ((memcg =3D mem_cgroup_iter(root, memcg, NULL))); > +} > + > +static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) > +{ > + struct reclaim_state *reclaim_state =3D current->reclaim_state; > + struct mem_cgroup *root =3D sc->target_mem_cgroup; > + unsigned long nr_reclaimed, nr_scanned; > + bool reclaimable =3D false; > + > +again: > + memset(&sc->nr, 0, sizeof(sc->nr)); > + > + nr_reclaimed =3D sc->nr_reclaimed; > + nr_scanned =3D sc->nr_scanned; > + > + shrink_node_memcgs(pgdat, sc); > =20 > if (reclaim_state) { > sc->nr_reclaimed +=3D reclaim_state->reclaimed_slab; > @@ -2793,7 +2801,7 @@ static bool shrink_node(pg_data_t *pgdat, struct sc= an_control *sc) > } > =20 > /* Record the subtree's reclaim efficiency */ > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, true, > + vmpressure(sc->gfp_mask, root, true, Maybe target? Or target_memcg? The word root is associated with the root cg= roup. Other than root the patch looks good to me: Reviewed-by: Roman Gushchin