* [PATCH 1/4 V2 net-next] cpumask: add cpumask_weight_andnot()
2024-01-22 16:00 [PATCH 0/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
@ 2024-01-22 16:00 ` Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 2/4 V2 net-next] cpumask: define cleanup function for cpumasks Souradeep Chakrabarti
` (2 subsequent siblings)
3 siblings, 0 replies; 9+ messages in thread
From: Souradeep Chakrabarti @ 2024-01-22 16:00 UTC (permalink / raw)
To: kys, haiyangz, wei.liu, decui, davem, edumazet, kuba, pabeni,
longli, yury.norov, leon, cai.huoqing, ssengar, vkuznets, tglx,
linux-hyperv, netdev, linux-kernel, linux-rdma
Cc: schakrabarti, paulros
From: Yury Norov <yury.norov@gmail.com>
Similarly to cpumask_weight_and(), cpumask_weight_andnot() is a handy
helper that may help to avoid creating an intermediate mask just to
calculate number of bits that set in a 1st given mask, and clear in 2nd
one.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
---
include/linux/bitmap.h | 12 ++++++++++++
include/linux/cpumask.h | 13 +++++++++++++
lib/bitmap.c | 7 +++++++
3 files changed, 32 insertions(+)
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 99451431e4d6..5814e9ee40ba 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -54,6 +54,7 @@ struct device;
* bitmap_full(src, nbits) Are all bits set in *src?
* bitmap_weight(src, nbits) Hamming Weight: number set bits
* bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap
+ * bitmap_weight_andnot(src1, src2, nbits) Hamming Weight of andnot'ed bitmap
* bitmap_set(dst, pos, nbits) Set specified bit area
* bitmap_clear(dst, pos, nbits) Clear specified bit area
* bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
@@ -169,6 +170,8 @@ bool __bitmap_subset(const unsigned long *bitmap1,
unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
+unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
+ const unsigned long *bitmap2, unsigned int nbits);
void __bitmap_set(unsigned long *map, unsigned int start, int len);
void __bitmap_clear(unsigned long *map, unsigned int start, int len);
@@ -425,6 +428,15 @@ unsigned long bitmap_weight_and(const unsigned long *src1,
return __bitmap_weight_and(src1, src2, nbits);
}
+static __always_inline
+unsigned long bitmap_weight_andnot(const unsigned long *src1,
+ const unsigned long *src2, unsigned int nbits)
+{
+ if (small_const_nbits(nbits))
+ return hweight_long(*src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits));
+ return __bitmap_weight_andnot(src1, src2, nbits);
+}
+
static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
unsigned int nbits)
{
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index cfb545841a2c..228c23eb36d2 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -719,6 +719,19 @@ static inline unsigned int cpumask_weight_and(const struct cpumask *srcp1,
return bitmap_weight_and(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits);
}
+/**
+ * cpumask_weight_andnot - Count of bits in (*srcp1 & ~*srcp2)
+ * @srcp1: the cpumask to count bits (< nr_cpu_ids) in.
+ * @srcp2: the cpumask to count bits (< nr_cpu_ids) in.
+ *
+ * Return: count of bits set in both *srcp1 and *srcp2
+ */
+static inline unsigned int cpumask_weight_andnot(const struct cpumask *srcp1,
+ const struct cpumask *srcp2)
+{
+ return bitmap_weight_andnot(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits);
+}
+
/**
* cpumask_shift_right - *dstp = *srcp >> n
* @dstp: the cpumask result
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 09522af227f1..b97692854966 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -348,6 +348,13 @@ unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
}
EXPORT_SYMBOL(__bitmap_weight_and);
+unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
+ const unsigned long *bitmap2, unsigned int bits)
+{
+ return BITMAP_WEIGHT(bitmap1[idx] & ~bitmap2[idx], bits);
+}
+EXPORT_SYMBOL(__bitmap_weight_andnot);
+
void __bitmap_set(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);
--
2.34.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH 2/4 V2 net-next] cpumask: define cleanup function for cpumasks
2024-01-22 16:00 [PATCH 0/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 1/4 V2 net-next] cpumask: add cpumask_weight_andnot() Souradeep Chakrabarti
@ 2024-01-22 16:00 ` Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 3/4 V2 net-next] net: mana: add a function to spread IRQs per CPUs Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
3 siblings, 0 replies; 9+ messages in thread
From: Souradeep Chakrabarti @ 2024-01-22 16:00 UTC (permalink / raw)
To: kys, haiyangz, wei.liu, decui, davem, edumazet, kuba, pabeni,
longli, yury.norov, leon, cai.huoqing, ssengar, vkuznets, tglx,
linux-hyperv, netdev, linux-kernel, linux-rdma
Cc: schakrabarti, paulros
From: Yury Norov <yury.norov@gmail.com>
Now we can simplify code that allocates cpumasks for local needs.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
include/linux/cpumask.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 228c23eb36d2..1c29947db848 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -7,6 +7,7 @@
* set of CPUs in a system, one bit position per CPU number. In general,
* only nr_cpu_ids (<= NR_CPUS) bits are valid.
*/
+#include <linux/cleanup.h>
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/bitmap.h>
@@ -990,6 +991,8 @@ static inline bool cpumask_available(cpumask_var_t mask)
}
#endif /* CONFIG_CPUMASK_OFFSTACK */
+DEFINE_FREE(free_cpumask_var, struct cpumask *, if (_T) free_cpumask_var(_T));
+
/* It's common to want to use cpu_all_mask in struct member initializers,
* so it has to refer to an address rather than a pointer. */
extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
--
2.34.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 3/4 V2 net-next] net: mana: add a function to spread IRQs per CPUs
2024-01-22 16:00 [PATCH 0/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 1/4 V2 net-next] cpumask: add cpumask_weight_andnot() Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 2/4 V2 net-next] cpumask: define cleanup function for cpumasks Souradeep Chakrabarti
@ 2024-01-22 16:00 ` Souradeep Chakrabarti
2024-01-22 16:00 ` [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
3 siblings, 0 replies; 9+ messages in thread
From: Souradeep Chakrabarti @ 2024-01-22 16:00 UTC (permalink / raw)
To: kys, haiyangz, wei.liu, decui, davem, edumazet, kuba, pabeni,
longli, yury.norov, leon, cai.huoqing, ssengar, vkuznets, tglx,
linux-hyperv, netdev, linux-kernel, linux-rdma
Cc: schakrabarti, paulros
From: Yury Norov <yury.norov@gmail.com>
Souradeep investigated that the driver performs faster if IRQs are
spread on CPUs with the following heuristics:
1. No more than one IRQ per CPU, if possible;
2. NUMA locality is the second priority;
3. Sibling dislocality is the last priority.
Let's consider this topology:
Node 0 1
Core 0 1 2 3
CPU 0 1 2 3 4 5 6 7
The most performant IRQ distribution based on the above topology
and heuristics may look like this:
IRQ Nodes Cores CPUs
0 1 0 0-1
1 1 1 2-3
2 1 0 0-1
3 1 1 2-3
4 2 2 4-5
5 2 3 6-7
6 2 2 4-5
7 2 3 6-7
The irq_setup() routine introduced in this patch leverages the
for_each_numa_hop_mask() iterator and assigns IRQs to sibling groups
as described above.
According to [1], for NUMA-aware but sibling-ignorant IRQ distribution
based on cpumask_local_spread() performance test results look like this:
./ntttcp -r -m 16
NTTTCP for Linux 1.4.0
---------------------------------------------------------
08:05:20 INFO: 17 threads created
08:05:28 INFO: Network activity progressing...
08:06:28 INFO: Test run completed.
08:06:28 INFO: Test cycle finished.
08:06:28 INFO: ##### Totals: #####
08:06:28 INFO: test duration :60.00 seconds
08:06:28 INFO: total bytes :630292053310
08:06:28 INFO: throughput :84.04Gbps
08:06:28 INFO: retrans segs :4
08:06:28 INFO: cpu cores :192
08:06:28 INFO: cpu speed :3799.725MHz
08:06:28 INFO: user :0.05%
08:06:28 INFO: system :1.60%
08:06:28 INFO: idle :96.41%
08:06:28 INFO: iowait :0.00%
08:06:28 INFO: softirq :1.94%
08:06:28 INFO: cycles/byte :2.50
08:06:28 INFO: cpu busy (all) :534.41%
For NUMA- and sibling-aware IRQ distribution, the same test works
15% faster:
./ntttcp -r -m 16
NTTTCP for Linux 1.4.0
---------------------------------------------------------
08:08:51 INFO: 17 threads created
08:08:56 INFO: Network activity progressing...
08:09:56 INFO: Test run completed.
08:09:56 INFO: Test cycle finished.
08:09:56 INFO: ##### Totals: #####
08:09:56 INFO: test duration :60.00 seconds
08:09:56 INFO: total bytes :741966608384
08:09:56 INFO: throughput :98.93Gbps
08:09:56 INFO: retrans segs :6
08:09:56 INFO: cpu cores :192
08:09:56 INFO: cpu speed :3799.791MHz
08:09:56 INFO: user :0.06%
08:09:56 INFO: system :1.81%
08:09:56 INFO: idle :96.18%
08:09:56 INFO: iowait :0.00%
08:09:56 INFO: softirq :1.95%
08:09:56 INFO: cycles/byte :2.25
08:09:56 INFO: cpu busy (all) :569.22%
[1] https://lore.kernel.org/all/20231211063726.GA4977@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net/
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Co-developed-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
---
.../net/ethernet/microsoft/mana/gdma_main.c | 29 +++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index d33b27214539..05a0ac054823 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -1249,6 +1249,35 @@ void mana_gd_free_res_map(struct gdma_resource *r)
r->size = 0;
}
+static __maybe_unused int irq_setup(unsigned int *irqs, unsigned int len, int node)
+{
+ const struct cpumask *next, *prev = cpu_none_mask;
+ cpumask_var_t cpus __free(free_cpumask_var);
+ int cpu, weight;
+
+ if (!alloc_cpumask_var(&cpus, GFP_KERNEL))
+ return -ENOMEM;
+
+ rcu_read_lock();
+ for_each_numa_hop_mask(next, node) {
+ weight = cpumask_weight_andnot(next, prev);
+ while (weight > 0) {
+ cpumask_andnot(cpus, next, prev);
+ for_each_cpu(cpu, cpus) {
+ if (len-- == 0)
+ goto done;
+ irq_set_affinity_and_hint(*irqs++, topology_sibling_cpumask(cpu));
+ cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
+ --weight;
+ }
+ }
+ prev = next;
+ }
+done:
+ rcu_read_unlock();
+ return 0;
+}
+
static int mana_gd_setup_irqs(struct pci_dev *pdev)
{
unsigned int max_queues_per_port = num_online_cpus();
--
2.34.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores
2024-01-22 16:00 [PATCH 0/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
` (2 preceding siblings ...)
2024-01-22 16:00 ` [PATCH 3/4 V2 net-next] net: mana: add a function to spread IRQs per CPUs Souradeep Chakrabarti
@ 2024-01-22 16:00 ` Souradeep Chakrabarti
2024-01-24 1:03 ` Jakub Kicinski
2024-01-24 15:20 ` Yury Norov
3 siblings, 2 replies; 9+ messages in thread
From: Souradeep Chakrabarti @ 2024-01-22 16:00 UTC (permalink / raw)
To: kys, haiyangz, wei.liu, decui, davem, edumazet, kuba, pabeni,
longli, yury.norov, leon, cai.huoqing, ssengar, vkuznets, tglx,
linux-hyperv, netdev, linux-kernel, linux-rdma
Cc: schakrabarti, paulros, Souradeep Chakrabarti
Existing MANA design assigns IRQ to every CPU, including sibling
hyper-threads. This may cause multiple IRQs to be active simultaneously
in the same core and may reduce the network performance.
Improve the performance by assigning IRQ to non sibling CPUs in local
NUMA node. The performance improvement we are getting using ntttcp with
following patch is around 15 percent against existing design and
approximately 11 percent, when trying to assign one IRQ in each core
across NUMA nodes, if enough cores are present.
The change will improve the performance for the system
with high number of CPU, where number of CPUs in a node is more than
64 CPUs. Nodes with 64 CPUs or less than 64 CPUs will not be affected
by this change.
The performance study was done using ntttcp tool in Azure.
The node had 2 nodes with 32 cores each, total 128 vCPU and number of channels
were 32 for 32 RX rings.
The below table shows a comparison between existing design and new
design:
IRQ node-num core-num CPU performance(%)
1 0 | 0 0 | 0 0 | 0-1 0
2 0 | 0 0 | 1 1 | 2-3 3
3 0 | 0 1 | 2 2 | 4-5 10
4 0 | 0 1 | 3 3 | 6-7 15
5 0 | 0 2 | 4 4 | 8-9 15
---
---
25 0 | 0 12| 24 24| 48-49 12
---
32 0 | 0 15| 31 31| 62-63 12
33 0 | 0 16| 0 32| 0-1 10
---
64 0 | 0 31| 31 63| 62-63 0
Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
---
.../net/ethernet/microsoft/mana/gdma_main.c | 61 +++++++++++++++----
1 file changed, 50 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 05a0ac054823..1332db9a08eb 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -1249,7 +1249,7 @@ void mana_gd_free_res_map(struct gdma_resource *r)
r->size = 0;
}
-static __maybe_unused int irq_setup(unsigned int *irqs, unsigned int len, int node)
+static int irq_setup(unsigned int *irqs, unsigned int len, int node)
{
const struct cpumask *next, *prev = cpu_none_mask;
cpumask_var_t cpus __free(free_cpumask_var);
@@ -1280,13 +1280,16 @@ static __maybe_unused int irq_setup(unsigned int *irqs, unsigned int len, int no
static int mana_gd_setup_irqs(struct pci_dev *pdev)
{
- unsigned int max_queues_per_port = num_online_cpus();
struct gdma_context *gc = pci_get_drvdata(pdev);
+ unsigned int max_queues_per_port;
struct gdma_irq_context *gic;
unsigned int max_irqs, cpu;
- int nvec, irq;
+ int start_irq_index = 1;
+ int nvec, *irqs, irq;
int err, i = 0, j;
+ cpus_read_lock();
+ max_queues_per_port = num_online_cpus();
if (max_queues_per_port > MANA_MAX_NUM_QUEUES)
max_queues_per_port = MANA_MAX_NUM_QUEUES;
@@ -1294,8 +1297,18 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
max_irqs = max_queues_per_port + 1;
nvec = pci_alloc_irq_vectors(pdev, 2, max_irqs, PCI_IRQ_MSIX);
- if (nvec < 0)
+ if (nvec < 0) {
+ cpus_read_unlock();
return nvec;
+ }
+ if (nvec <= num_online_cpus())
+ start_irq_index = 0;
+
+ irqs = kmalloc_array((nvec - start_irq_index), sizeof(int), GFP_KERNEL);
+ if (!irqs) {
+ err = -ENOMEM;
+ goto free_irq_vector;
+ }
gc->irq_contexts = kcalloc(nvec, sizeof(struct gdma_irq_context),
GFP_KERNEL);
@@ -1323,17 +1336,41 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
goto free_irq;
}
- err = request_irq(irq, mana_gd_intr, 0, gic->name, gic);
- if (err)
- goto free_irq;
-
- cpu = cpumask_local_spread(i, gc->numa_node);
- irq_set_affinity_and_hint(irq, cpumask_of(cpu));
+ if (!i) {
+ err = request_irq(irq, mana_gd_intr, 0, gic->name, gic);
+ if (err)
+ goto free_irq;
+
+ /* If number of IRQ is one extra than number of online CPUs,
+ * then we need to assign IRQ0 (hwc irq) and IRQ1 to
+ * same CPU.
+ * Else we will use different CPUs for IRQ0 and IRQ1.
+ * Also we are using cpumask_local_spread instead of
+ * cpumask_first for the node, because the node can be
+ * mem only.
+ */
+ if (start_irq_index) {
+ cpu = cpumask_local_spread(i, gc->numa_node);
+ irq_set_affinity_and_hint(irq, cpumask_of(cpu));
+ } else {
+ irqs[start_irq_index] = irq;
+ }
+ } else {
+ irqs[i - start_irq_index] = irq;
+ err = request_irq(irqs[i - start_irq_index], mana_gd_intr, 0,
+ gic->name, gic);
+ if (err)
+ goto free_irq;
+ }
}
+ err = irq_setup(irqs, (nvec - start_irq_index), gc->numa_node);
+ if (err)
+ goto free_irq;
+
gc->max_num_msix = nvec;
gc->num_msix_usable = nvec;
-
+ cpus_read_unlock();
return 0;
free_irq:
@@ -1346,8 +1383,10 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
}
kfree(gc->irq_contexts);
+ kfree(irqs);
gc->irq_contexts = NULL;
free_irq_vector:
+ cpus_read_unlock();
pci_free_irq_vectors(pdev);
return err;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores
2024-01-22 16:00 ` [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
@ 2024-01-24 1:03 ` Jakub Kicinski
2024-01-25 6:05 ` Souradeep Chakrabarti
2024-01-24 15:20 ` Yury Norov
1 sibling, 1 reply; 9+ messages in thread
From: Jakub Kicinski @ 2024-01-24 1:03 UTC (permalink / raw)
To: Souradeep Chakrabarti
Cc: kys, haiyangz, wei.liu, decui, davem, edumazet, pabeni, longli,
yury.norov, leon, cai.huoqing, ssengar, vkuznets, tglx,
linux-hyperv, netdev, linux-kernel, linux-rdma, schakrabarti,
paulros
On Mon, 22 Jan 2024 08:00:59 -0800 Souradeep Chakrabarti wrote:
> IRQ node-num core-num CPU performance(%)
> 1 0 | 0 0 | 0 0 | 0-1 0
> 2 0 | 0 0 | 1 1 | 2-3 3
> 3 0 | 0 1 | 2 2 | 4-5 10
> 4 0 | 0 1 | 3 3 | 6-7 15
> 5 0 | 0 2 | 4 4 | 8-9 15
> ---
> ---
Please don't use --- as a line, indent it or use ... because git am
uses --- as a commit message separator. The commit message will get
cut off at the first one of those if we try to apply this.
--
pw-bot: cr
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores
2024-01-24 1:03 ` Jakub Kicinski
@ 2024-01-25 6:05 ` Souradeep Chakrabarti
0 siblings, 0 replies; 9+ messages in thread
From: Souradeep Chakrabarti @ 2024-01-25 6:05 UTC (permalink / raw)
To: Jakub Kicinski
Cc: kys, haiyangz, wei.liu, decui, davem, edumazet, pabeni, longli,
yury.norov, leon, cai.huoqing, ssengar, vkuznets, tglx,
linux-hyperv, netdev, linux-kernel, linux-rdma, schakrabarti,
paulros
On Tue, Jan 23, 2024 at 05:03:32PM -0800, Jakub Kicinski wrote:
> On Mon, 22 Jan 2024 08:00:59 -0800 Souradeep Chakrabarti wrote:
> > IRQ node-num core-num CPU performance(%)
> > 1 0 | 0 0 | 0 0 | 0-1 0
> > 2 0 | 0 0 | 1 1 | 2-3 3
> > 3 0 | 0 1 | 2 2 | 4-5 10
> > 4 0 | 0 1 | 3 3 | 6-7 15
> > 5 0 | 0 2 | 4 4 | 8-9 15
> > ---
> > ---
>
> Please don't use --- as a line, indent it or use ... because git am
> uses --- as a commit message separator. The commit message will get
> cut off at the first one of those if we try to apply this.
> --
Thanks for pointing, will fix it in next version.
- Souradeep
> pw-bot: cr
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores
2024-01-22 16:00 ` [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores Souradeep Chakrabarti
2024-01-24 1:03 ` Jakub Kicinski
@ 2024-01-24 15:20 ` Yury Norov
2024-01-25 6:07 ` Souradeep Chakrabarti
1 sibling, 1 reply; 9+ messages in thread
From: Yury Norov @ 2024-01-24 15:20 UTC (permalink / raw)
To: Souradeep Chakrabarti
Cc: kys, haiyangz, wei.liu, decui, davem, edumazet, kuba, pabeni,
longli, leon, cai.huoqing, ssengar, vkuznets, tglx, linux-hyperv,
netdev, linux-kernel, linux-rdma, schakrabarti, paulros
On Mon, Jan 22, 2024 at 08:00:59AM -0800, Souradeep Chakrabarti wrote:
> Existing MANA design assigns IRQ to every CPU, including sibling
> hyper-threads. This may cause multiple IRQs to be active simultaneously
> in the same core and may reduce the network performance.
>
> Improve the performance by assigning IRQ to non sibling CPUs in local
> NUMA node. The performance improvement we are getting using ntttcp with
> following patch is around 15 percent against existing design and
> approximately 11 percent, when trying to assign one IRQ in each core
> across NUMA nodes, if enough cores are present.
> The change will improve the performance for the system
> with high number of CPU, where number of CPUs in a node is more than
> 64 CPUs. Nodes with 64 CPUs or less than 64 CPUs will not be affected
> by this change.
>
> The performance study was done using ntttcp tool in Azure.
> The node had 2 nodes with 32 cores each, total 128 vCPU and number of channels
> were 32 for 32 RX rings.
>
> The below table shows a comparison between existing design and new
> design:
>
> IRQ node-num core-num CPU performance(%)
> 1 0 | 0 0 | 0 0 | 0-1 0
> 2 0 | 0 0 | 1 1 | 2-3 3
> 3 0 | 0 1 | 2 2 | 4-5 10
> 4 0 | 0 1 | 3 3 | 6-7 15
> 5 0 | 0 2 | 4 4 | 8-9 15
> ---
> ---
> 25 0 | 0 12| 24 24| 48-49 12
> ---
> 32 0 | 0 15| 31 31| 62-63 12
> 33 0 | 0 16| 0 32| 0-1 10
> ---
> 64 0 | 0 31| 31 63| 62-63 0
Did that omitted lines mean 5-24 : 15%, 25-31 : 12% and 33-63 : 10%?
Or that means that you didn't test those?
Would be nice to have full coverage...
Thanks,
Yury
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 4/4 V2 net-next] net: mana: Assigning IRQ affinity on HT cores
2024-01-24 15:20 ` Yury Norov
@ 2024-01-25 6:07 ` Souradeep Chakrabarti
0 siblings, 0 replies; 9+ messages in thread
From: Souradeep Chakrabarti @ 2024-01-25 6:07 UTC (permalink / raw)
To: Yury Norov
Cc: kys, haiyangz, wei.liu, decui, davem, edumazet, kuba, pabeni,
longli, leon, cai.huoqing, ssengar, vkuznets, tglx, linux-hyperv,
netdev, linux-kernel, linux-rdma, schakrabarti, paulros
On Wed, Jan 24, 2024 at 07:20:27AM -0800, Yury Norov wrote:
> On Mon, Jan 22, 2024 at 08:00:59AM -0800, Souradeep Chakrabarti wrote:
> > Existing MANA design assigns IRQ to every CPU, including sibling
> > hyper-threads. This may cause multiple IRQs to be active simultaneously
> > in the same core and may reduce the network performance.
> >
> > Improve the performance by assigning IRQ to non sibling CPUs in local
> > NUMA node. The performance improvement we are getting using ntttcp with
> > following patch is around 15 percent against existing design and
> > approximately 11 percent, when trying to assign one IRQ in each core
> > across NUMA nodes, if enough cores are present.
> > The change will improve the performance for the system
> > with high number of CPU, where number of CPUs in a node is more than
> > 64 CPUs. Nodes with 64 CPUs or less than 64 CPUs will not be affected
> > by this change.
> >
> > The performance study was done using ntttcp tool in Azure.
> > The node had 2 nodes with 32 cores each, total 128 vCPU and number of channels
> > were 32 for 32 RX rings.
> >
> > The below table shows a comparison between existing design and new
> > design:
> >
> > IRQ node-num core-num CPU performance(%)
> > 1 0 | 0 0 | 0 0 | 0-1 0
> > 2 0 | 0 0 | 1 1 | 2-3 3
> > 3 0 | 0 1 | 2 2 | 4-5 10
> > 4 0 | 0 1 | 3 3 | 6-7 15
> > 5 0 | 0 2 | 4 4 | 8-9 15
> > ---
> > ---
> > 25 0 | 0 12| 24 24| 48-49 12
> > ---
> > 32 0 | 0 15| 31 31| 62-63 12
> > 33 0 | 0 16| 0 32| 0-1 10
> > ---
> > 64 0 | 0 31| 31 63| 62-63 0
>
> Did that omitted lines mean 5-24 : 15%, 25-31 : 12% and 33-63 : 10%?
They are same like you have mentioned, so I have skipped those ranges.
Whereever the major changes were there, I have put them.
So it is the full coverage only skimmed a little.
> Or that means that you didn't test those?
>
> Would be nice to have full coverage...
>
> Thanks,
> Yury
^ permalink raw reply [flat|nested] 9+ messages in thread