Re: [PATCH v3] irqchip: gicv3-its: Use NUMA aware memory allocation for ITS tables

[Ganapatrao Kulkarni]

Hi Shameer,

Patch looks OK to me, please feel free to add,
Reviewed-by: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxx>

On Thu, Dec 13, 2018 at 5:25 PM Marc Zyngier <marc.zyngier@xxxxxxx> wrote:
>
> On 13/12/2018 10:59, Shameer Kolothum wrote:
> > From: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
> >
> > The NUMA node information is visible to ITS driver but not being used
> > other than handling hardware errata. ITS/GICR hardware accesses to the
> > local NUMA node is usually quicker than the remote NUMA node. How slow
> > the remote NUMA accesses are depends on the implementation details.
> >
> > This patch allocates memory for ITS management tables and command
> > queue from the corresponding NUMA node using the appropriate NUMA
> > aware functions. This change improves the performance of the ITS
> > tables read latency on systems where it has more than one ITS block,
> > and with the slower inter node accesses.
> >
> > Apache Web server benchmarking using ab tool on a HiSilicon D06
> > board with multiple numa mem nodes shows Time per request and
> > Transfer rate improvements of ~3.6% with this patch.
> >
> > Signed-off-by: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
> > Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
> > ---
> >
> > This is to revive the patch originally sent by Shanker[1] and
> > to back it up with a benchmark test. Any further testing of
> > this is most welcome.
> >
> > v2-->v3
> >  -Addressed comments to use page_address().
> >  -Added Benchmark results to commit log.
> >  -Removed T-by from Ganapatrao for now.
> >
> > v1-->v2
> >  -Edited commit text.
> >  -Added Ganapatrao's tested-by.
> >
> > Benchmark test details:
> > --------------------------------
> > Test Setup:
> > -D06 with dimm on node 0(Sock#0) and 3 (Sock#1).
> > -ITS belongs to numa node 0.
> > -Filesystem mounted on a PCIe NVMe based disk.
> > -Apache server installed on D06.
> > -Running ab benchmark test in concurrency mode from a remote m/c
> >  connected to D06 via  hns3(PCIe) n/w port.
> >  "ab -k -c 750 -n 2000000 http://10.202.225.188/";
> >
> > Test results are avg. of 15 runs.
> >
> > For 4.20-rc1  Kernel,
> > ----------------------------
> > Time per request(mean, concurrent)  = 0.02753[ms]
> > Transfer Rate = 416501[Kbytes/sec]
> >
> > For 4.20-rc1 +  this patch,
> > ----------------------------------
> > Time per request(mean, concurrent)  = 0.02653[ms]
> > Transfer Rate = 431954[Kbytes/sec]
> >
> > % improvement ~3.6%
> >
> > vmstat shows around 170K-200K interrupts per second.
> >
> > ~# vmstat 1 -w
> > procs -----------------------memory-- -  -system--
> >  r  b         swpd         free            in
> >  5  0            0     30166724          102794
> >  9  0            0     30141828          171148
> >  5  0            0     30150160          207185
> > 13  0            0     30145924          175691
> > 15  0            0     30140792          145250
> > 13  0            0     30135556          201879
> > 13  0            0     30134864          192391
> > 10  0            0     30133632          168880
> > ....
> >
> > [1] https://patchwork.kernel.org/patch/9833339/
>
> The figures certainly look convincing. I'd need someone from Cavium to
> benchmark it on their hardware and come back with results so that we can
> make a decision on this.

Hi Marc,
My setup got altered during Lab migration from Cavium to Marvell office.
I don't think, i will have same setup anytime soon.

>
> Thanks,
>
>         M.
> --
> Jazz is not dead. It just smells funny...

Thanks,
Ganapat