> On Jan 26, 2021, at 1:18 AM, Lu Baolu <baolu...@linux.intel.com> wrote:
>
> On 2021/1/26 3:31, Chuck Lever wrote:
>>> On Jan 25, 2021, at 12:39 PM, Chuck Lever <chuck.le...@oracle.com> wrote:
>>>
>>> Hello Lu -
>>>
>>> Many thanks for your prototype.
>>>
>>>
>>>> On Jan 24, 2021, at 9:38 PM, Lu Baolu <baolu...@linux.intel.com> wrote:
>>>>
>>>> This patch series is only for Request-For-Testing purpose. It aims to
>>>> fix the performance regression reported here.
>>>>
>>>> https://lore.kernel.org/linux-iommu/d81314ed-5673-44a6-b597-090e3cb83...@oracle.com/
>>>>
>>>> The first two patches are borrowed from here.
>>>>
>>>> https://lore.kernel.org/linux-iommu/20210107122909.16317-1-yong...@mediatek.com/
>>>>
>>>> Please kindly help to verification.
>>>>
>>>> Best regards,
>>>> baolu
>>>>
>>>> Lu Baolu (1):
>>>> iommu/vt-d: Add iotlb_sync_map callback
>>>>
>>>> Yong Wu (2):
>>>> iommu: Move iotlb_sync_map out from __iommu_map
>>>> iommu: Add iova and size as parameters in iotlb_sync_map
>>>>
>>>> drivers/iommu/intel/iommu.c | 86 +++++++++++++++++++++++++------------
>>>> drivers/iommu/iommu.c | 23 +++++++---
>>>> drivers/iommu/tegra-gart.c | 7 ++-
>>>> include/linux/iommu.h | 3 +-
>>>> 4 files changed, 83 insertions(+), 36 deletions(-)
>>>
>>> Here are results with the NFS client at stock v5.11-rc5 and the
>>> NFS server at v5.10, showing the regression I reported earlier.
>>>
>>> Children see throughput for 12 initial writers = 4534582.00 kB/sec
>>> Parent sees throughput for 12 initial writers = 4458145.56 kB/sec
>>> Min throughput per process = 373101.59 kB/sec
>>> Max throughput per process = 382669.50 kB/sec
>>> Avg throughput per process = 377881.83 kB/sec
>>> Min xfer = 1022720.00 kB
>>> CPU Utilization: Wall time 2.787 CPU time 1.922 CPU
>>> utilization 68.95 %
>>>
>>>
>>> Children see throughput for 12 rewriters = 4542003.12 kB/sec
>>> Parent sees throughput for 12 rewriters = 4538024.19 kB/sec
>>> Min throughput per process = 374672.00 kB/sec
>>> Max throughput per process = 383983.78 kB/sec
>>> Avg throughput per process = 378500.26 kB/sec
>>> Min xfer = 1022976.00 kB
>>> CPU utilization: Wall time 2.733 CPU time 1.947 CPU
>>> utilization 71.25 %
>>>
>>>
>>> Children see throughput for 12 readers = 4568632.03 kB/sec
>>> Parent sees throughput for 12 readers = 4563672.02 kB/sec
>>> Min throughput per process = 376727.56 kB/sec
>>> Max throughput per process = 383783.91 kB/sec
>>> Avg throughput per process = 380719.34 kB/sec
>>> Min xfer = 1029376.00 kB
>>> CPU utilization: Wall time 2.733 CPU time 1.898 CPU
>>> utilization 69.46 %
>>>
>>>
>>> Children see throughput for 12 re-readers = 4610702.78 kB/sec
>>> Parent sees throughput for 12 re-readers = 4606135.66 kB/sec
>>> Min throughput per process = 381532.78 kB/sec
>>> Max throughput per process = 387072.53 kB/sec
>>> Avg throughput per process = 384225.23 kB/sec
>>> Min xfer = 1034496.00 kB
>>> CPU utilization: Wall time 2.711 CPU time 1.910 CPU
>>> utilization 70.45 %
>>>
>>> Here's the NFS client at v5.11-rc5 with your series applied.
>>> The NFS server remains at v5.10:
>>>
>>> Children see throughput for 12 initial writers = 4434778.81 kB/sec
>>> Parent sees throughput for 12 initial writers = 4408190.69 kB/sec
>>> Min throughput per process = 367865.28 kB/sec
>>> Max throughput per process = 371134.38 kB/sec
>>> Avg throughput per process = 369564.90 kB/sec
>>> Min xfer = 1039360.00 kB
>>> CPU Utilization: Wall time 2.842 CPU time 1.904 CPU
>>> utilization 66.99 %
>>>
>>>
>>> Children see throughput for 12 rewriters = 4476870.69 kB/sec
>>> Parent sees throughput for 12 rewriters = 4471701.48 kB/sec
>>> Min throughput per process = 370985.34 kB/sec
>>> Max throughput per process = 374752.28 kB/sec
>>> Avg throughput per process = 373072.56 kB/sec
>>> Min xfer = 1038592.00 kB
>>> CPU utilization: Wall time 2.801 CPU time 1.902 CPU
>>> utilization 67.91 %
>>>
>>>
>>> Children see throughput for 12 readers = 5865268.88 kB/sec
>>> Parent sees throughput for 12 readers = 5854519.73 kB/sec
>>> Min throughput per process = 487766.81 kB/sec
>>> Max throughput per process = 489623.88 kB/sec
>>> Avg throughput per process = 488772.41 kB/sec
>>> Min xfer = 1044736.00 kB
>>> CPU utilization: Wall time 2.144 CPU time 1.895 CPU
>>> utilization 88.41 %
>>>
>>>
>>> Children see throughput for 12 re-readers = 5847438.62 kB/sec
>>> Parent sees throughput for 12 re-readers = 5839292.18 kB/sec
>>> Min throughput per process = 485835.03 kB/sec
>>> Max throughput per process = 488702.12 kB/sec
>>> Avg throughput per process = 487286.55 kB/sec
>>> Min xfer = 1042688.00 kB
>>> CPU utilization: Wall time 2.148 CPU time 1.909 CPU
>>> utilization 88.84 %
>>>
>>> NFS READ throughput is almost fully restored. A normal-looking throughput
>>> result, copied from the previous thread, is:
>>>
>>> Children see throughput for 12 readers = 5921370.94 kB/sec
>>> Parent sees throughput for 12 readers = 5914106.69 kB/sec
>>>
>>> The NFS WRITE throughput result appears to be unchanged, or slightly
>>> worse than before. I don't have an explanation for this result. I applied
>>> your patches on the NFS server also without noting improvement.
>> Function-boundary tracing shows some interesting results.
>> # trace-cmd record -e rpcrdma -e iommu -p function_graph --max-graph-depth=5
>> -g dma_map_sg_attrs
>> Some 120KB SGLs are DMA-mapped in a single call to __iommu_map(). Other SGLs
>> of
>> the same size need as many as one __iommu_map() call per SGL element (which
>> would be 30 for a 120KB SGL).
>> In v5.10, intel_map_sg() was structured such that an SGL is always handled
>> with
>> a single call to domain_mapping() and thus always just a single TLB flush.
>> My amateur theorizing suggests that the SGL element coalescing done in
>> __iommu_map_sg() is not working as well as intel_map_sg() used to, which
>> results
>> in more calls to domain_mapping(). Not only does that take longer, but it
>> creates
>> many more DMA maps. Could that also have some impact on device TLB resources?
>
> It seems that more domain_mapping() calls are not caused by
> __iommu_map_sg() but __iommu_map().
>
> Can you please test below changes? It call intel_iommu_map() directly
> instead of __iommu_map().
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index f5a236e63ded..660d5744a117 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4916,7 +4916,7 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain,
> struct device *dev,
> }
> #endif
>
> -static int intel_iommu_map(struct iommu_domain *domain,
> +int intel_iommu_map(struct iommu_domain *domain,
> unsigned long iova, phys_addr_t hpa,
> size_t size, int iommu_prot, gfp_t gfp)
> {
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 3d099a31ddca..a1b41fd3fb4e 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -23,8 +23,13 @@
> #include <linux/property.h>
> #include <linux/fsl/mc.h>
> #include <linux/module.h>
> +#include <linux/intel-iommu.h>
> #include <trace/events/iommu.h>
>
> +extern int intel_iommu_map(struct iommu_domain *domain,
> + unsigned long iova, phys_addr_t hpa,
> + size_t size, int iommu_prot, gfp_t gfp);
> +
> static struct kset *iommu_group_kset;
> static DEFINE_IDA(iommu_group_ida);
>
> @@ -2553,8 +2558,7 @@ static size_t __iommu_map_sg(struct iommu_domain
> *domain, unsigned long iova,
> phys_addr_t s_phys = sg_phys(sg);
>
> if (len && s_phys != start + len) {
> - ret = __iommu_map(domain, iova + mapped, start,
> - len, prot, gfp);
> + ret = intel_iommu_map(domain, iova + mapped, start,
> len, prot, gfp);
>
> if (ret)
> goto out_err;
>
> Does it change anything?
I removed yesterday's 3-patch series, and applied the above.
Not a full restoration, but interesting nonetheless.
Children see throughput for 12 initial writers = 4852657.22 kB/sec
Parent sees throughput for 12 initial writers = 4826730.38 kB/sec
Min throughput per process = 403196.09 kB/sec
Max throughput per process = 406071.47 kB/sec
Avg throughput per process = 404388.10 kB/sec
Min xfer = 1041408.00 kB
CPU Utilization: Wall time 2.596 CPU time 2.047 CPU
utilization 78.84 %
Children see throughput for 12 rewriters = 4853900.22 kB/sec
Parent sees throughput for 12 rewriters = 4848623.31 kB/sec
Min throughput per process = 403380.81 kB/sec
Max throughput per process = 405478.53 kB/sec
Avg throughput per process = 404491.68 kB/sec
Min xfer = 1042944.00 kB
CPU utilization: Wall time 2.589 CPU time 2.048 CPU
utilization 79.12 %
Children see throughput for 12 readers = 4938124.12 kB/sec
Parent sees throughput for 12 readers = 4932862.08 kB/sec
Min throughput per process = 408768.81 kB/sec
Max throughput per process = 413879.25 kB/sec
Avg throughput per process = 411510.34 kB/sec
Min xfer = 1036800.00 kB
CPU utilization: Wall time 2.536 CPU time 1.906 CPU
utilization 75.16 %
Children see throughput for 12 re-readers = 4992115.16 kB/sec
Parent sees throughput for 12 re-readers = 4986102.07 kB/sec
Min throughput per process = 411103.00 kB/sec
Max throughput per process = 420302.97 kB/sec
Avg throughput per process = 416009.60 kB/sec
Min xfer = 1025792.00 kB
CPU utilization: Wall time 2.497 CPU time 1.887 CPU
utilization 75.57 %
NFS WRITE throughput improves significantly. NFS READ throughput
improves somewhat, but not to the degree it did with yesterday's
patch series.
function_graph shows a single intel_iommu_map() is used more
frequently, but the following happens on occasion:
395.678889: funcgraph_entry: | dma_map_sg_attrs() {
395.678889: funcgraph_entry: | iommu_dma_map_sg() {
395.678890: funcgraph_entry: 0.257 us | iommu_get_dma_domain();
395.678890: funcgraph_entry: 0.255 us |
iommu_dma_deferred_attach();
395.678891: funcgraph_entry: |
iommu_dma_sync_sg_for_device() {
395.678891: funcgraph_entry: 0.253 us | dev_is_untrusted();
395.678891: funcgraph_exit: 0.773 us | }
395.678892: funcgraph_entry: 0.250 us | dev_is_untrusted();
395.678893: funcgraph_entry: | iommu_dma_alloc_iova() {
395.678893: funcgraph_entry: | alloc_iova_fast() {
395.678893: funcgraph_entry: 0.255 us |
_raw_spin_lock_irqsave();
395.678894: funcgraph_entry: 0.375 us | __lock_text_start();
395.678894: funcgraph_exit: 1.435 us | }
395.678895: funcgraph_exit: 2.002 us | }
395.678895: funcgraph_entry: 0.252 us | dma_info_to_prot();
395.678895: funcgraph_entry: | iommu_map_sg_atomic() {
395.678896: funcgraph_entry: | __iommu_map_sg() {
395.678896: funcgraph_entry: 1.675 us | intel_iommu_map();
395.678898: funcgraph_entry: 1.365 us | intel_iommu_map();
395.678900: funcgraph_entry: 1.373 us | intel_iommu_map();
395.678901: funcgraph_entry: 1.378 us | intel_iommu_map();
395.678903: funcgraph_entry: 1.380 us | intel_iommu_map();
395.678905: funcgraph_entry: 1.380 us | intel_iommu_map();
395.678906: funcgraph_entry: 1.378 us | intel_iommu_map();
395.678908: funcgraph_entry: 1.380 us | intel_iommu_map();
395.678910: funcgraph_entry: 1.345 us | intel_iommu_map();
395.678911: funcgraph_entry: 1.342 us | intel_iommu_map();
395.678913: funcgraph_entry: 1.342 us | intel_iommu_map();
395.678915: funcgraph_entry: 1.395 us | intel_iommu_map();
395.678916: funcgraph_entry: 1.343 us | intel_iommu_map();
395.678918: funcgraph_entry: 1.350 us | intel_iommu_map();
395.678920: funcgraph_entry: 1.395 us | intel_iommu_map();
395.678921: funcgraph_entry: 1.342 us | intel_iommu_map();
395.678923: funcgraph_entry: 1.350 us | intel_iommu_map();
395.678924: funcgraph_entry: 1.345 us | intel_iommu_map();
395.678926: funcgraph_entry: 1.345 us | intel_iommu_map();
395.678928: funcgraph_entry: 1.340 us | intel_iommu_map();
395.678929: funcgraph_entry: 1.342 us | intel_iommu_map();
395.678931: funcgraph_entry: 1.335 us | intel_iommu_map();
395.678933: funcgraph_entry: 1.345 us | intel_iommu_map();
395.678934: funcgraph_entry: 1.337 us | intel_iommu_map();
395.678936: funcgraph_entry: 1.305 us | intel_iommu_map();
395.678938: funcgraph_entry: 1.380 us | intel_iommu_map();
395.678939: funcgraph_entry: 1.365 us | intel_iommu_map();
395.678941: funcgraph_entry: 1.370 us | intel_iommu_map();
395.678943: funcgraph_entry: 1.365 us | intel_iommu_map();
395.678945: funcgraph_entry: 1.482 us | intel_iommu_map();
395.678946: funcgraph_exit: + 50.753 us | }
395.678947: funcgraph_exit: + 51.348 us | }
395.678947: funcgraph_exit: + 57.975 us | }
395.678948: funcgraph_exit: + 58.700 us | }
395.678953: xprtrdma_mr_map: task:64127@5 mr.id=104 nents=30
122880@0xc5e467fde9380000:0xc0011103 (TO_DEVICE)
395.678953: xprtrdma_chunk_read: task:64127@5 pos=148
122880@0xc5e467fde9380000:0xc0011103 (more)
--
Chuck Lever
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