I take hours to shutdown ATS.

Why ?

----------------------------
Lampo
best regards


 Original Message
Sender: Steve Malenfant<[email protected]>
Recipient: [email protected]<[email protected]>
Date: Wednesday, Sep 7, 2016 04:33
Subject: Re: Huge Page sizing for traffic server

5.3.2 with huge page patches. I would not use THP...

I want to reserve pages used by ATS and mainly using it because the page table 
gets huge with 256GB of ram cache and I takes hours to shutdown ATS. You want 
hose pages cached in TLB.

I'm using because I'm forced to right now. But I'm testing to see what works 
best.

On Tuesday, September 6, 2016, Bin Liu(刘斌6) 
<[email protected]<mailto:[email protected]>> wrote:

Hello:


    5.3.2 or 6.2.0 ?



    Does 5.3.2 support HugePage ?


    5.3.2 only support Transparent Huge Page ?


    How about just use Transparent Huge Page ? or prefer to close it ?



    Does it related to fragment size ?


    We have encountered slow request with Transparent Huge Page(5.3.2). It 
blocked ink_freelist_new (malloc) and ink_freelist_free (init list) sometimes 
even more than 1 second holding vol lock. We guess it caused by defragment and 
long time search for continuous memory larger than size(HugePage). Could anyone 
analyse it ? Or why it when malloc and init list?


    When should we use HugePage or TransparentHugePage?

——————————————
Lampo
best regards


 Original Message
Sender: Steve 
Malenfant<[email protected]<javascript:_e(%7B%7D,'cvml','[email protected]');>>
Recipient: 
users<[email protected]<javascript:_e(%7B%7D,'cvml','[email protected]');>>
Date: Tuesday, Sep 6, 2016 20:24
Subject: Huge Page sizing for traffic server

I'm testing 5.3.2 with huge page enabled. Here's the setup :

CONFIG proxy.config.cache.ram_cache.size = INT 137438953472 (128GB)

Normally I would need 65536 pages (2048KB in size), But I added ~12 GB extra :
vm.nr_hugepages=72000

The results are good. no performance issues (on the current build I have), the 
PageTables size is hovering around 8000 kB (PageTables:         8440 kB). 
Before, this would go higher than 200,000kB creating some memory management 
issues every 32-33 minutes and causing high load average on the server (on code 
with hugepages modifications).

After a weekend of load testing just so the RAM Cache is fully filled up, I see 
that all 72,000 pages are being used :

[root@psp6cdedge03 ~]# cat /proc/meminfo | grep Huge
AnonHugePages:         0 kB
HugePages_Total:   72000
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB

If you enable Huge Pages, you'll see that traffic server doesn't report that 
RES memory in top anymore and can be a bit confusing...

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
7386 ats       20   0  154g 1.0g  39m S 45.0  0.4   2590:29 [ET_NET 0]

This build also have the NUMA fix, before you'd see a bunch of numa_miss and 
numa_foreign :

# numastat
                           node0           node1
numa_hit             25212626736     25457088463
numa_miss                      0               0
numa_foreign                   0               0
interleave_hit          12464334        12464369
local_node           25212625913     25444350193
other_node                   823        12738270


How much Huge Pages do I need extras? Is there some other parameters that would 
help me sizing the number of reserve huge page I need?

Thanks,

Steve

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