| Message ID | 1532416745-9926-1-git-send-email-lirongqing@baidu.com |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | netfilter: avoid stalls in nf_ct_alloc_hashtable | expand |
Li RongQing <lirongqing@baidu.com> wrote: > when system forks a process with CLONE_NEWNET flag under the > high memory pressure, it will trigger memory reclaim and stall > for a long time because nf_ct_alloc_hashtable need to allocate > high-order memory at that time. The calltrace as below: > nf_ct_alloc_hashtable > nf_conntrack_init_net This call trace is from a kernel < 4.7. commit 56d52d4892d0e478a005b99ed10d0a7f488ea8c1 netfilter: conntrack: use a single hashtable for all namespaces removed per-netns hash table.
> -----邮件原件----- > 发件人: Florian Westphal [mailto:fw@strlen.de] > 发送时间: 2018年7月24日 17:20 > 收件人: Li,Rongqing <lirongqing@baidu.com> > 抄送: netdev@vger.kernel.org; pablo@netfilter.org; > kadlec@blackhole.kfki.hu; fw@strlen.de > 主题: Re: [PATCH] netfilter: avoid stalls in nf_ct_alloc_hashtable > > Li RongQing <lirongqing@baidu.com> wrote: > > when system forks a process with CLONE_NEWNET flag under the high > > memory pressure, it will trigger memory reclaim and stall for a long > > time because nf_ct_alloc_hashtable need to allocate high-order memory > > at that time. The calltrace as below: > > > nf_ct_alloc_hashtable > > nf_conntrack_init_net > > This call trace is from a kernel < 4.7. > Sorry; it is > commit 56d52d4892d0e478a005b99ed10d0a7f488ea8c1 > netfilter: conntrack: use a single hashtable for all namespaces > > removed per-netns hash table. Thanks, Your patch fixes my issue; My patch may be able to reduce stall when modprobe nf module in memory stress, Do you think this patch has any value? -RongQing
Hello! On 7/24/2018 10:19 AM, Li RongQing wrote: > when system forks a process with CLONE_NEWNET flag under the > high memory pressure, it will trigger memory reclaim and stall > for a long time because nf_ct_alloc_hashtable need to allocate > high-order memory at that time. The calltrace as below: > > delay_tsc > __delay > _raw_spin_lock > _spin_lock > mmu_shrink > shrink_slab > zone_reclaim > get_page_from_freelist > __alloc_pages_nodemask > alloc_pages_current > __get_free_pages > nf_ct_alloc_hashtable > nf_conntrack_init_net > setup_net > copy_net_ns > create_new_namespaces > copy_namespaces > copy_process > do_fork > sys_clone > stub_clone > __clone > > not use the directly memory reclaim flag to avoid stall You mean "do not use"? > Signed-off-by: Ni Xun <nixun@baidu.com> > Signed-off-by: Zhang Yu <zhangyu31@baidu.com> > Signed-off-by: Wang Li <wangli39@baidu.com> > Signed-off-by: Li RongQing <lirongqing@baidu.com> [...] MBR, Sergei
On 07/24/2018 02:50 AM, Li,Rongqing wrote: > Thanks, Your patch fixes my issue; > > My patch may be able to reduce stall when modprobe nf module in memory stress, > Do you think this patch has any value? Only if you make it use kvzalloc()/kvfree() Thanks.
> > On 07/24/2018 02:50 AM, Li,Rongqing wrote: > > > Thanks, Your patch fixes my issue; > > > > My patch may be able to reduce stall when modprobe nf module in > memory > > stress, Do you think this patch has any value? > > Only if you make it use kvzalloc()/kvfree() > > Thanks. I will send v2, free to give your signature. Thanks, -RongQing
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8a113ca1eea2..672c5960530d 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2120,8 +2120,8 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) return NULL; sz = nr_slots * sizeof(struct hlist_nulls_head); - hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, - get_order(sz)); + hash = (void *)__get_free_pages((GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | + __GFP_NOWARN | __GFP_ZERO, get_order(sz)); if (!hash) hash = vzalloc(sz);