From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 501EA6B026A for ; Mon, 30 Jan 2017 11:36:31 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id x4so8945671wme.3 for ; Mon, 30 Jan 2017 08:36:31 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id z20si13995145wmz.148.2017.01.30.08.36.29 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 30 Jan 2017 08:36:30 -0800 (PST) Subject: Re: [PATCH 6/9] net: use kvmalloc with __GFP_REPEAT rather than open coded variant References: <20170130094940.13546-1-mhocko@kernel.org> <20170130094940.13546-7-mhocko@kernel.org> From: Vlastimil Babka Message-ID: <9e1f34ef-1038-cf0b-95c2-1df64f1a541b@suse.cz> Date: Mon, 30 Jan 2017 17:36:27 +0100 MIME-Version: 1.0 In-Reply-To: <20170130094940.13546-7-mhocko@kernel.org> Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko , Andrew Morton Cc: David Rientjes , Mel Gorman , Johannes Weiner , Al Viro , linux-mm@kvack.org, LKML , Michal Hocko , Eric Dumazet , netdev@vger.kernel.org On 01/30/2017 10:49 AM, Michal Hocko wrote: > From: Michal Hocko > > fq_alloc_node, alloc_netdev_mqs and netif_alloc* open code kmalloc > with vmalloc fallback. Use the kvmalloc variant instead. Keep the > __GFP_REPEAT flag based on explanation from Eric: > " > At the time, tests on the hardware I had in my labs showed that > vmalloc() could deliver pages spread all over the memory and that was a > small penalty (once memory is fragmented enough, not at boot time) > " > > The way how the code is constructed means, however, that we prefer to go > and hit the OOM killer before we fall back to the vmalloc for requests > <=32kB (with 4kB pages) in the current code. This is rather disruptive for > something that can be achived with the fallback. On the other hand > __GFP_REPEAT doesn't have any useful semantic for these requests. So the > effect of this patch is that requests smaller than 64kB will fallback to > vmalloc esier now. easier Although it's somewhat of an euphemism when compared to "basically never" :) > > Cc: Eric Dumazet > Cc: netdev@vger.kernel.org > Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka > --- > net/core/dev.c | 24 +++++++++--------------- > net/sched/sch_fq.c | 12 +----------- > 2 files changed, 10 insertions(+), 26 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index be11abac89b3..707e730821a6 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -7081,12 +7081,10 @@ static int netif_alloc_rx_queues(struct net_device *dev) > > BUG_ON(count < 1); > > - rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); > - if (!rx) { > - rx = vzalloc(sz); > - if (!rx) > - return -ENOMEM; > - } > + rx = kvzalloc(sz, GFP_KERNEL | __GFP_REPEAT); > + if (!rx) > + return -ENOMEM; > + > dev->_rx = rx; > > for (i = 0; i < count; i++) > @@ -7123,12 +7121,10 @@ static int netif_alloc_netdev_queues(struct net_device *dev) > if (count < 1 || count > 0xffff) > return -EINVAL; > > - tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); > - if (!tx) { > - tx = vzalloc(sz); > - if (!tx) > - return -ENOMEM; > - } > + tx = kvzalloc(sz, GFP_KERNEL | __GFP_REPEAT); > + if (!tx) > + return -ENOMEM; > + > dev->_tx = tx; > > netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL); > @@ -7661,9 +7657,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, > /* ensure 32-byte alignment of whole construct */ > alloc_size += NETDEV_ALIGN - 1; > > - p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); > - if (!p) > - p = vzalloc(alloc_size); > + p = kvzalloc(alloc_size, GFP_KERNEL | __GFP_REPEAT); > if (!p) > return NULL; > > diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c > index a4f738ac7728..594f77d89f6c 100644 > --- a/net/sched/sch_fq.c > +++ b/net/sched/sch_fq.c > @@ -624,16 +624,6 @@ static void fq_rehash(struct fq_sched_data *q, > q->stat_gc_flows += fcnt; > } > > -static void *fq_alloc_node(size_t sz, int node) > -{ > - void *ptr; > - > - ptr = kmalloc_node(sz, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN, node); > - if (!ptr) > - ptr = vmalloc_node(sz, node); > - return ptr; > -} > - > static void fq_free(void *addr) > { > kvfree(addr); > @@ -650,7 +640,7 @@ static int fq_resize(struct Qdisc *sch, u32 log) > return 0; > > /* If XPS was setup, we can allocate memory on right NUMA node */ > - array = fq_alloc_node(sizeof(struct rb_root) << log, > + array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_REPEAT, > netdev_queue_numa_node_read(sch->dev_queue)); > if (!array) > return -ENOMEM; > -- 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/ . Don't email: email@kvack.org