[tkernel2 commit c6f2e27f7ad]
add SO_MARK2 to get the MARK of flow
Signed-off-by: brookxu <brookxu@tencent.com>
Signed-off-by: Zhiping Du <zhipingdu@tencent.com>
This commit add cpu.offline to cpu cgroup, echo 1 > cpu.offline would
convert all tasks under this cgroup to offline task. Beside, a new
sysctl sysctl_sched_bt_ignore_cpubind is added, which makes offline
tasks ignoring CPU binding and running on any CPU.
Signed-off-by: Xiaoming Gao <newtongao@tencent.com>
Signed-off-by: Hua Liu <shookliu@tencent.com>
Signed-off-by: Xiaogguang Chen <xiaoggchen@tencent.com>
Signed-off-by: Zhiguang Peng <zgpeng@tencent.com>
Signed-off-by: Bin Fan <tombinfan@tencent.com>
Signed-off-by: He Chen <heddchen@tencent.com>
Since 'commit f719e3754ee2 ("ipvs: drop first packet to
redirect conntrack")', when a new TCP connection meet
the conditions that need reschedule, the first syn packet
is dropped, this cause one second latency for the new
connection, more discussion about this problem can easy
search from google, such as:
1)One second connection delay in masque
https://marc.info/?t=151683118100004&r=1&w=2
2)IPVS low throughput #70747
https://github.com/kubernetes/kubernetes/issues/70747
3)Apache Bench can fill up ipvs service proxy in seconds #544https://github.com/cloudnativelabs/kube-router/issues/544
4)Additional 1s latency in `host -> service IP -> pod`
https://github.com/kubernetes/kubernetes/issues/90854
5)kube-proxy ipvs conn_reuse_mode setting causes errors
with high load from single client
https://github.com/kubernetes/kubernetes/issues/81775
The root cause is when the old session is expired, the
conntrack related to the session is dropped by
ip_vs_conn_drop_conntrack. The code is as follows:
```
static void ip_vs_conn_expire(struct timer_list *t)
{
...
if ((cp->flags & IP_VS_CONN_F_NFCT) &&
!(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
/* Do not access conntracks during subsys cleanup
* because nf_conntrack_find_get can not be used after
* conntrack cleanup for the net.
*/
smp_rmb();
if (ipvs->enable)
ip_vs_conn_drop_conntrack(cp);
}
...
}
```
As shown in the code, only when condition (cp->flags & IP_VS_CONN_F_NFCT)
is true, the function ip_vs_conn_drop_conntrack will be called.
So we optimize this by following steps (Administrators
can choose the following optimization by setting
net.ipv4.vs.conn_reuse_old_conntrack=1):
1) erase the IP_VS_CONN_F_NFCT flag (it is safely because
no packets will use the old session)
2) call ip_vs_conn_expire_now to release the old session,
then the related conntrack will not be dropped
3) then ipvs unnecessary to drop the first syn packet, it
just continue to pass the syn packet to the next process,
create a new ipvs session, and the new session will related
to the old conntrack(which is reopened by conntrack as a new
one), the next whole things is just as normal as that the old
session isn't used to exist.
The above processing has no problems except for passive FTP,
for passive FTP situation, ipvs can judging from
condition (atomic_read(&cp->n_control)) and condition (cp->control).
So, for other conditions(means not FTP), ipvs should give users
the right to choose，they can choose a high performance one processing
logical by setting net.ipv4.vs.conn_reuse_old_conntrack=1. It is necessary
because most business scenarios (such as kubernetes) are very sensitive
to TCP short connection latency.
This patch has been verified on our thousands of kubernets
node servers on Tencent Inc.
Signed-off-by: YangYuxi <yx.atom1@gmail.com>
year 2015 d752c364571743d696c2a54a449ce77550c35ac5
year 2016 f719e3754ee2f7275437e61a6afd520181fdd43b
current only fix it in bpf mode. It will later be promoted to ipvs mode.
The key is that add a ref count in ct so that old/new ip_vs_conn can share it
without packet loss.
Test case
./wrk http 1.0 test, the cps increases from 1.5K to 30K.
2) solve no route to host bug
when conn_reuse_mode = 0, new connection may be redirect to rs with weight=0
if client port reuse. This cause icmp no route to host if the rs is
terminating
Test case:
1. wrk http1.0 from client
2. set rs to zero on lb, then kill the rs
in ipvs mode, you can see icmp error like
14:17:28.509454 IP 10.0.0.4 > 10.0.0.17: ICMP host 172.16.0.16 unreachable, length 68
in bpf mode, this is fixed.
Signed-off-by: jianmingfan <jianmingfan@tencent.com>
Offline tasks (BT tasks) may have some performance impact to online
tasks.
In this commit, we introduce Intel RDT features to limit offline tasks
L3 cache usage to avoid the influence caused by offline tasks.
Signed-off-by: Xiaoguang Chen <xiaoggchen@tencent.com>
Signed-off-by: He Chen <heddchen@tencent.com>
use lightweight track method to count free objects in
slub, remove heavy logic in spin_lock_irqsave.
Signed-off-by: Xiaoming Gao <newtongao@tencent.com>
commit <aac8d41cd438f25bf3110fc6b98f1d16d7dbc169>
commit <85009b4f5f0399669a44f07cb9a5622c0e71d419>
When someone calls wakeup_flusher_threads() or
wakeup_flusher_threads_bdi(), they schedule writeback of all dirty
pages in the system (or on that bdi). If we are tight on memory, we
can get tons of these queued from kswapd/vmscan. This causes (at
least) two problems:
1) We consume a ton of memory just allocating writeback work items.
We've seen as much as 600 million of these writeback work items
pending. That's a lot of memory to pointlessly hold hostage,
while the box is under memory pressure.
2) We spend so much time processing these work items, that we
introduce a softlockup in writeback processing. This is because
each of the writeback work items don't end up doing any work (it's
hard when you have millions of identical ones coming in to the
flush machinery), so we just sit in a tight loop pulling work
items and deleting/freeing them.
Fix this by adding a 'start_all' bit to the writeback structure, and
set that when someone attempts to flush all dirty pages. The bit is
cleared when we start writeback on that work item. If the bit is
already set when we attempt to queue !nr_pages writeback, then we
simply ignore it.
This provides us one full flush in flight, with one pending as well,
and makes for more efficient handling of this type of writeback.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
When there is no rs, kernel will print:
ipvs will print IPVS: rr: TCP xxxxxX - no destination available
But this is common in k8s.
So add a sysctl to allow user ignore this error.
Signed-off-by: Hongbo Li <herberthbli@tencent.com>
It does the following
* To bypass netfilter and conntrack in BPF mode
** Add mode=1 switch in modprobe to enable BPF mode
** Register different set of netfilter hooks in BPF mode so that
incoming and response packets are handled in NF PRE-ROUTING
bypassing conntrack hooks.
** Don't access skb->dst if it is null.
** Force route in handle_response
** Call ip_finish_output directly instead of Netfilter api.
** User space shall set /proc/sys/net/ipv4/vs/conntrack to be zero
** Call ip defragment during pre-route when needed!
* To interact with BPF map
** ip_vs_conn_new_bpf add entries into BPF map
** ip_vs_conn_unlink_bpf del them
** in lc,wlc,rr,wrr scheduler, avoid loopback traffic since BPF can't
handle it currently.
* Interface
** Add file ip_vs_bpf_proc.c to pass BPF map id into IPVS.
Add the max_map_count isolation switch kernel.isolate_max_map_count;
The isolation of max_map_count is turned on by default. If you want
to turn it off, set kernel.isolate_max_map_count to 0;
Signed-off-by: Zhiguang Peng <zgpeng@tencent.com>
Kernel now supports cgroup bps and iops hard limit by io-throttling.
But that's not a scalable way, because block devices' bandwith is
always changing over time.
This patch dynamically adjusts bps limit of each blkio cgroup according
to its pre-set weight. Additionally, if a process has not issued any io
request during a time window, its weight will be shared by other processes
until its next io request.
Signed-off-by: Lei Chen <lennychen@tencent.com>
The offline scheduler named BT sched is based on the CFS scheduler. We
also use the rb-tree as the run queue to save the runnable tasks. And the
vruntime concept is also used in the offline scheduler. And the priority
of offline scheduler is from 140 to 179. So now the schedulers in the
kernel are as follows: stop, RT, CFS, BT and idle.
Signed-off-by: Xiaoming Gao <newtongao@tencent.com>
Signed-off-by: Hua Liu <shookliu@tencent.com>
Signed-off-by: Xiaogguang Chen <xiaoggchen@tencent.com>
Signed-off-by: Zhiguang Peng <zgpeng@tencent.com>
Signed-off-by: Bin Fan <tombinfan@tencent.com>
Signed-off-by: He Chen <heddchen@tencent.com>
This patch adds the infrastructure required to support cephfs quotas as it
is currently implemented in the ceph fuse client. Cephfs quotas can be
set on any directory, and can restrict the number of bytes or the number
of files stored beneath that point in the directory hierarchy.
Quotas are set using the extended attributes 'ceph.quota.max_files' and
'ceph.quota.max_bytes', and can be removed by setting these attributes to
'0'.
Link: http://tracker.ceph.com/issues/22372
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Which control whether to resend requests if timeout. Further more,
the patch adds a debugfs file which can change this option during mount.
Signed-off-by: Liu Yu <allanyuliu@tencent.com>
When osd requests timeout, the defaut action is discarding all timeout
requests and reseting the connection. It then returns IO errors to
userspace.
The patch re-send all timeout requests instead of discarding,
so that make the timeout transparent to userspace.
Signed-off-by: Liu Yu <allanyuliu@tencent.com>
Based on upstream commit:
d63bae0 KVM: X86: Add kvm hypervisor init time platform setup callback
aaffcfd KVM: X86: Implement PV IPIs in linux guest
Implement paravirtual apic hooks to enable PV IPIs for KVM if the "send IPI"
hypercall is available. The hypercall lets a guest send IPIs, with
at most 128 destinations per hypercall in 64-bit mode and 64 vCPUs per
hypercall in 32-bit mode.
Signed-off-by: loobinliu <loobinliu@tencent.com>
The value of the cpuset.stat process field will be abnormal in
some scenarios. The reason for this problem is that the sum of
process_counts may be negative for several cpus.
Signed-off-by: brookxu <brookxu@tencent.com>
tcp_rto_min,tcp_rto_max control the parameters of them.
remember that the min value of tcp_rto_min is 4ms which
be used to be div by RTO_MAX.
Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: Fuhai Wang <fuhaiwang@tencent.com>
Signed-off-by: Xiaoming Gao <newtongao@tencent.com>
In order to facilitate each container to obtain its own IO statistics,
we implement per blkcg diskstats and expose some data from the host
into the container such as io_ticks.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
[upstream commit 5f3e2bf008c2221478101ee72f5cb4654b9fc363]
Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.
This forces the stack to send packets with a very high network/cpu
overhead.
Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.
In some cases, it can be useful to increase the minimal value
to a saner value.
We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.
Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f118 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.
We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.
CVE-2019-11479 -- tcp mss hardcoded to 48
[upstream commit: 967c05aee439e6e5d7d805e195b3a20ef5c433d6]
tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
If mtu probing is enabled tcp_mtu_probing() could very well end up
with a too small MSS.
Use the new sysctl tcp_min_snd_mss to make sure MSS search
is performed in an acceptable range.
Signed-off-by: Zhiping Du <zhipingdu@tencent.com>
[upstream commit f070ef2ac66716357066b683fb0baf55f8191a2e]
Jonathan Looney reported that a malicious peer can force a sender
to fragment its retransmit queue into tiny skbs, inflating memory
usage and/or overflow 32bit counters.
TCP allows an application to queue up to sk_sndbuf bytes,
so we need to give some allowance for non malicious splitting
of retransmit queue.
A new SNMP counter is added to monitor how many times TCP
did not allow to split an skb if the allowance was exceeded.
Note that this counter might increase in the case applications
use SO_SNDBUF socket option to lower sk_sndbuf.
CVE-2019-11478 : tcp_fragment, prevent fragmenting a packet when the
socket is already using more than half the allowed space
Signed-off-by: Zhiping Du <zhipingdu@tencent.com>
[upstream commit 3b4929f65b0d8249f19a50245cd88ed1a2f78cff]
Jonathan Looney reported that TCP can trigger the following crash
in tcp_shifted_skb() :
BUG_ON(tcp_skb_pcount(skb) < pcount);
This can happen if the remote peer has advertized the smallest
MSS that linux TCP accepts : 48
An skb can hold 17 fragments, and each fragment can hold 32KB
on x86, or 64KB on PowerPC.
This means that the 16bit witdh of TCP_SKB_CB(skb)->tcp_gso_segs
can overflow.
Note that tcp_sendmsg() builds skbs with less than 64KB
of payload, so this problem needs SACK to be enabled.
SACK blocks allow TCP to coalesce multiple skbs in the retransmit
queue, thus filling the 17 fragments to maximal capacity.
CVE-2019-11477 -- u16 overflow of TCP_SKB_CB(skb)->tcp_gso_segs
[upstream commit cd4ffa93f16efea290bb70537f98f518e1927e63]
tcp: fix fack_count accounting on
tcp_shift_skb_data()
v4.15 or since commit 737ff314563 ("tcp: use sequence distance to
detect reordering") had switched from the packet-based FACK tracking
to sequence-based.
v4.14 and older still have the old logic and hence on
tcp_skb_shift_data() needs to retain its original logic and have
@fack_count in sync. In other words, we keep the increment of pcount
with
tcp_skb_pcount(skb) to later used that to update fack_count. To make it
more explicit we track the new skb that gets incremented to pcount in
@next_pcount, and we get to avoid the constant invocation of
tcp_skb_pcount(skb) all together.
Fixes: a5f1faa40101 ("tcp: limit payload size of sacked skbs")
Fixes: 832d11c5cd07 ("tcp: Try to restore large SKBs while SACK processing")
Signed-off-by: Zhiping Du <zhipingdu@tencent.com>
When use-gss-proxy is set to 1, write_gssp will lead to 2 get_net calls
in gssp_rpc_create, the paired put_net calls are supposed to be made
in rpcsec_gss_net_ops->exit i.e. rpcsec_gss_exit_net, but this will
never happen because rpcsec_gss_exit_net (via ops_exit_list) is called
by cleanup_net and cleanup_net will never run unless net->count becomes
0, since the paired put_net calls of gssp_rpc_create are not made yet,
net->count cannot drop to 0. This is dead lock situation.
This fix introduced a new method i.e. evict in struct proc_ns_operations,
which is called in nsfs_evict, moving rpcsec_gss_exit_net into the code
path of nsfs_evict gives it a chance to run.
Signed-off-by: Wenbin Zeng <wenbinzeng@tencent.com>
add /proc/sys/vm/vm_pagecache_limit_async interface which
allow page caches reclaimed in kpclimitd, it will not consume
work threads runtime, but oom may be occured. it's closed default.
Signed-off-by: Zhiping Du <zhipingdu@tencent.com>
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
We add cpuinfo and stat for each container which
used for docker to get cpu stat just for current
container.
Signed-off-by: Xiaoming Gao <newtongao@tencent.com>
Signed-off-by: Weiwei Li <nuonuoli@tencent.com>
Signed-off-by: Liu Hua <shookliu@tencent.com>
the print_fatal_signals sysctl can only dump fatal signals from receiver's side,
cannot find who and why send these fatal signals, so add a new sysctl
print_fatal_signals_src_dst to switch dump fatal signals from sender side.
Signed-off-by: Xiaoming Gao <newtongao@tencent.com>
create a pid mapping data to parent processes in file /proc/$PID/status
create a proc file (/proc/$PID/hostinfo), mapping pid data to host pid
Signed-off-by: Lorin Liu <lorinliu@tencent.com>
Hongbo Li