RE: [PATCH v4] irqchip: gicv3-its: Use NUMA aware memory allocation for ITS tables

From: Shameerali Kolothum Thodi
Date: Tue Feb 19 2019 - 06:05:51 EST


Hi Marc,

A gentle reminder on this one...

Thanks,
Shameer

> -----Original Message-----
> From: Linuxarm [mailto:linuxarm-bounces@xxxxxxxxxx] On Behalf Of Shameer
> Kolothum
> Sent: 14 January 2019 09:50
> To: marc.zyngier@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Cc: gkulkarni@xxxxxxxxxxx; suzuki.poulose@xxxxxxx; Linuxarm
> <linuxarm@xxxxxxxxxx>; Robert.Richter@xxxxxxxxxx;
> shankerd@xxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: [PATCH v4] irqchip: gicv3-its: Use NUMA aware memory allocation for
> ITS tables
>
> 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>
> Reviewed-by: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxx>
> ---
>
> 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.
>
> v3-->v4
> -Addressed comments on alloc_pages_node() and page_address() usage.
> -Rebased on 5.0-rc1
> -Added Ganapatrao's R-by.
>
> 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/
>
> drivers/irqchip/irq-gic-v3-its.c | 26 ++++++++++++++++----------
> 1 file changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index db20e99..5df59ad 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -1737,6 +1737,7 @@ static int its_setup_baser(struct its_node *its,
> struct its_baser *baser,
> u64 type = GITS_BASER_TYPE(val);
> u64 baser_phys, tmp;
> u32 alloc_pages;
> + struct page *page;
> void *base;
>
> retry_alloc_baser:
> @@ -1749,10 +1750,11 @@ static int its_setup_baser(struct its_node *its,
> struct its_baser *baser,
> order = get_order(GITS_BASER_PAGES_MAX * psz);
> }
>
> - base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
> - if (!base)
> + page = alloc_pages_node(its->numa_node, GFP_KERNEL | __GFP_ZERO,
> order);
> + if (!page)
> return -ENOMEM;
>
> + base = (void *)page_address(page);
> baser_phys = virt_to_phys(base);
>
> /* Check if the physical address of the memory is above 48bits */
> @@ -2236,7 +2238,8 @@ static struct its_baser *its_get_baser(struct
> its_node *its, u32 type)
> return NULL;
> }
>
> -static bool its_alloc_table_entry(struct its_baser *baser, u32 id)
> +static bool its_alloc_table_entry(struct its_node *its,
> + struct its_baser *baser, u32 id)
> {
> struct page *page;
> u32 esz, idx;
> @@ -2256,7 +2259,8 @@ static bool its_alloc_table_entry(struct its_baser
> *baser, u32 id)
>
> /* Allocate memory for 2nd level table */
> if (!table[idx]) {
> - page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
> get_order(baser->psz));
> + page = alloc_pages_node(its->numa_node, GFP_KERNEL |
> __GFP_ZERO,
> + get_order(baser->psz));
> if (!page)
> return false;
>
> @@ -2287,7 +2291,7 @@ static bool its_alloc_device_table(struct its_node
> *its, u32 dev_id)
> if (!baser)
> return (ilog2(dev_id) < its->device_ids);
>
> - return its_alloc_table_entry(baser, dev_id);
> + return its_alloc_table_entry(its, baser, dev_id);
> }
>
> static bool its_alloc_vpe_table(u32 vpe_id)
> @@ -2311,7 +2315,7 @@ static bool its_alloc_vpe_table(u32 vpe_id)
> if (!baser)
> return false;
>
> - if (!its_alloc_table_entry(baser, vpe_id))
> + if (!its_alloc_table_entry(its, baser, vpe_id))
> return false;
> }
>
> @@ -2345,7 +2349,7 @@ static struct its_device *its_create_device(struct
> its_node *its, u32 dev_id,
> nr_ites = max(2, nvecs);
> sz = nr_ites * its->ite_size;
> sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
> - itt = kzalloc(sz, GFP_KERNEL);
> + itt = kzalloc_node(sz, GFP_KERNEL, its->numa_node);
> if (alloc_lpis) {
> lpi_map = its_lpi_alloc(nvecs, &lpi_base, &nr_lpis);
> if (lpi_map)
> @@ -3486,6 +3490,7 @@ static int __init its_probe_one(struct resource *res,
> void __iomem *its_base;
> u32 val, ctlr;
> u64 baser, tmp, typer;
> + struct page *page;
> int err;
>
> its_base = ioremap(res->start, resource_size(res));
> @@ -3541,12 +3546,13 @@ static int __init its_probe_one(struct resource
> *res,
>
> its->numa_node = numa_node;
>
> - its->cmd_base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
> - get_order(ITS_CMD_QUEUE_SZ));
> - if (!its->cmd_base) {
> + page = alloc_pages_node(its->numa_node, GFP_KERNEL | __GFP_ZERO,
> + get_order(ITS_CMD_QUEUE_SZ));
> + if (!page) {
> err = -ENOMEM;
> goto out_free_its;
> }
> + its->cmd_base = (void *)page_address(page);
> its->cmd_write = its->cmd_base;
> its->fwnode_handle = handle;
> its->get_msi_base = its_irq_get_msi_base;
> --
> 2.7.4
>
>
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