kernel/freebsd: add NUMA domain selection for contigmem
PATCH 1/1 kernel/freebsd: add NUMA domain selection for contigmem
From: Kumar Sanghvi <[email protected]>
On multi-socket systems, DPDK applications pin their threads to cores on the socket local to the NIC, but the FreeBSD EAL reports all lcores and all contigmem memory as socket 0, so an application has no way to ask for local buffers. Physical placement is decided entirely by contigmem, which allocates its buffers at module load with contigmalloc(). That uses a round-robin domain policy, so the buffers can land on a remote domain, and every DMA transfer and packet copy then crosses the inter-socket interconnect.
Add a hw.contigmem.numa_domain loader tunable. When it is set to a domain number, every buffer is allocated from that domain with contigmalloc_domainset(DOMAINSET_FIXED()).
The placement is strict. If the domain cannot provide a buffer, the module load fails and the requested domain is reported, rather than buffers being silently placed elsewhere. An out-of-range value also fails the load. The default, -1, keeps the existing behaviour of allocating from any domain.
The tunable takes effect only at module load and is exposed read-only through sysctl. EAL socket reporting is unchanged.
Usage:
kenv hw.contigmem.numa_domain=1
kldload contigmem
Tested on FreeBSD 13.2, dual-socket Intel Xeon Gold 6442Y (Sapphire Rapids, 2 x 24 cores) with Intel E810 25G NICs attached to socket 1. A DPDK application on socket 1 received packets with a poll-mode driver and copied them to three packet-processing applications, also on socket 1, driven by httperf TCP traffic (1000 connections, 128 KB objects). Measured with Intel PCM (pcm, pcm-memory, pcm-numa) at steady state, default round-robin placement vs. all buffers in domain 1:
- remote memory bandwidth of the poll-mode thread:
~1800 MB/s -> ~0 MB/s
- incoming UPI traffic: 2340 MB/s -> 77 MB/s (-97%)
- power: 7 W lower (5 W CPU + 2 W DIMM)
--- .mailmap | 2 +- doc/guides/freebsd_gsg/build_dpdk.rst | 23 +++++++++++++++++ doc/guides/rel_notes/release_26_11.rst | 5 ++++ kernel/freebsd/contigmem/contigmem.c | 34 +++++++++++++++++++++++--- 4 files changed, 60 insertions(+), 4 deletions(-)
.mailmap +1 -1
@@ -915,7 +915,7 @@ Krzysztof Witek <[email protected]> Kuan Xu <[email protected]> Kuba Kozak <[email protected]> Kumar Amber <[email protected]> -Kumar Sanghvi <[email protected]> +Kumar Sanghvi <[email protected]> <[email protected]> Kumara Parameshwaran <[email protected]> <[email protected]> Kyle Larose <[email protected]> Kyo Liu <[email protected]>
doc/guides/freebsd_gsg/build_dpdk.rst +23 -0
@@ -107,6 +107,29 @@ Mapped buffers can be included in core dump using the following tunable:: Buffers typically hold data processed by the application, like network packets, which may contain sensitive information. +On multi-socket systems, the buffers can be allocated from a specific +NUMA domain using the following tunable:: + + hw.contigmem.numa_domain=d + +Where d is a domain number from 0 to ``vm.ndomains`` - 1. +Placing the buffers in the domain local to the NIC and to the cores +running the DPDK application avoids cross-socket memory traffic. +The default, -1, allocates buffers from any domain. +The placement is strict: the module fails to load +if the requested domain cannot provide all buffers +or if the value is out of range. +The tunable takes effect only when the module is loaded. +The NUMA domain of a device can be found using +``sysctl dev.<driver>.<unit>.%domain``, +for example ``sysctl dev.ice.0.%domain``. + +.. note:: + + The FreeBSD EAL reports all lcores and all contigmem memory as socket 0. + This tunable changes only the physical placement of the buffers; + applications should keep requesting memory from socket 0 or ``SOCKET_ID_ANY``. + The kernel environment variables can also be specified during boot by placing the following in ``/boot/loader.conf``:
doc/guides/rel_notes/release_26_11.rst +5 -0
@@ -55,6 +55,11 @@ New Features Also, make sure to start the actual text at the margin. ======================================================= +* **Added NUMA domain selection to the FreeBSD contigmem module.** + + Added the ``hw.contigmem.numa_domain`` tunable + to allocate contigmem buffers from a chosen NUMA domain. + * **Added division round up macro.** Added the ``RTE_DIV_ROUND_UP`` macro in ``rte_common.h``
kernel/freebsd/contigmem/contigmem.c +31 -3
@@ -20,6 +20,7 @@ __FBSDID("$FreeBSD$");#include <sys/sysctl.h> #include <sys/vmmeter.h> #include <sys/eventhandler.h> +#include <sys/domainset.h> #include <machine/bus.h>
@@ -59,10 +60,14 @@ static struct contigmem_buffer contigmem_buffers[RTE_CONTIGMEM_MAX_NUM_BUFS];static struct cdev *contigmem_cdev =NULL ;static int contigmem_refcnt; +/* -1 = any domain (default) */ +static int contigmem_numa_domain =-1 ; +TUNABLE_INT ("hw.contigmem.num_buffers" , &contigmem_num_buffers);TUNABLE_QUAD ("hw.contigmem.buffer_size" , &contigmem_buffer_size);TUNABLE_QUAD ("hw.contigmem.buffer_size_MB" , &contigmem_buffer_size_MB);TUNABLE_BOOL ("hw.contigmem.coredump_enable" , &contigmem_coredump_enable); +TUNABLE_INT ("hw.contigmem.numa_domain" , &contigmem_numa_domain); static SYSCTL_NODE(_hw, OID_AUTO, contigmem, CTLFLAG_RD, 0, "contigmem");
@@ -77,6 +82,9 @@ SYSCTL_INT(_hw_contigmem, OID_AUTO, num_references, CTLFLAG_RD, &contigmem_refcnt, 0, "Number of references to contigmem");SYSCTL_BOOL (_hw_contigmem,OID_AUTO , coredump_enable,CTLFLAG_RD , &contigmem_coredump_enable,0 ,"Include mapped buffers in core dump" ); +SYSCTL_INT (_hw_contigmem,OID_AUTO , numa_domain,CTLFLAG_RD , + &contigmem_numa_domain,0 , +"NUMA domain for buffer allocation (-1 = any domain)" ); static SYSCTL_NODE(_hw_contigmem, OID_AUTO, physaddr, CTLFLAG_RD, 0, "physaddr");
@@ -150,11 +158,31 @@ contigmem_load(void) goto error; } +if (contigmem_numa_domain <-1 || + contigmem_numa_domain >= vm_ndomains) { +printf ("contigmem: invalid numa_domain %d (valid: -1 to %d)\n" , + contigmem_numa_domain, vm_ndomains -1 ); + error =EINVAL ; + goto error; + } +for (i =0 ; i < contigmem_num_buffers; i++) { - addr =contigmalloc (contigmem_buffer_size,M_CONTIGMEM ,M_ZERO , -0 ,BUS_SPACE_MAXADDR , contigmem_buffer_size,0 ); +if (contigmem_numa_domain >=0 ) + addr =contigmalloc_domainset (contigmem_buffer_size, +M_CONTIGMEM , +DOMAINSET_FIXED (contigmem_numa_domain), +M_ZERO ,0 ,BUS_SPACE_MAXADDR , + contigmem_buffer_size,0 ); +else + addr =contigmalloc (contigmem_buffer_size,M_CONTIGMEM , +M_ZERO ,0 ,BUS_SPACE_MAXADDR , + contigmem_buffer_size,0 );if (addr ==NULL ) { -printf ("contigmalloc failed for buffer %d\n" , i); +if (contigmem_numa_domain >=0 ) +printf ("contigmem: buffer %d: no contiguous memory in NUMA domain %d\n" , + i, contigmem_numa_domain); +else +printf ("contigmalloc failed for buffer %d\n" , i); error =ENOMEM ; goto error; }
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