Re: [PATCH v2 2/3] pktgen: Add imix distribution bins

From: Nick Richardson
Date: Tue Aug 17 2021 - 19:55:41 EST

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On Tue, Aug 17, 2021 at 6:27 PM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> On 8/17/2021 3:17 PM, Nick Richardson wrote:
> > On Wed, 11 Aug 2021 at 00:32, Nicholas Richardson
> > <richardsonnick@xxxxxxxxxx> wrote:
> >>
> >> From: Nick Richardson <richardsonnick@xxxxxxxxxx>
> >>
> >> In order to represent the distribution of imix packet sizes, a
> >> pre-computed data structure is used. It features 100 (IMIX_PRECISION)
> >> "bins". Contiguous ranges of these bins represent the respective
> >> packet size of each imix entry. This is done to avoid the overhead of
> >> selecting the correct imix packet size based on the corresponding weights.
> >>
> >> Example:
> >> imix_weights 40,7 576,4 1500,1
> >> total_weight = 7 + 4 + 1 = 12
> >>
> >> pkt_size 40 occurs 7/total_weight = 58% of the time
> >> pkt_size 576 occurs 4/total_weight = 33% of the time
> >> pkt_size 1500 occurs 1/total_weight = 9% of the time
> >>
> >> We generate a random number between 0-100 and select the corresponding
> >> packet size based on the specified weights.
> >> Eg. random number = 358723895 % 100 = 65
> >> Selects the packet size corresponding to index:65 in the pre-computed
> >> imix_distribution array.
> >> An example of the pre-computed array is below:
> >>
> >> The imix_distribution will look like the following:
> >> 0 -> 0 (index of imix_entry.size == 40)
> >> 1 -> 0 (index of imix_entry.size == 40)
> >> 2 -> 0 (index of imix_entry.size == 40)
> >> [...] -> 0 (index of imix_entry.size == 40)
> >> 57 -> 0 (index of imix_entry.size == 40)
> >> 58 -> 1 (index of imix_entry.size == 576)
> >> [...] -> 1 (index of imix_entry.size == 576)
> >> 90 -> 1 (index of imix_entry.size == 576)
> >> 91 -> 2 (index of imix_entry.size == 1500)
> >> [...] -> 2 (index of imix_entry.size == 1500)
> >> 99 -> 2 (index of imix_entry.size == 1500)
> >>
> >> Create and use "bin" representation of the imix distribution.
> >>
> >> Signed-off-by: Nick Richardson <richardsonnick@xxxxxxxxxx>
> >> ---
> >> net/core/pktgen.c | 41 +++++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 41 insertions(+)
> >>
> >> diff --git a/net/core/pktgen.c b/net/core/pktgen.c
> >> index a7e45eaccef7..ac1de15000e2 100644
> >> --- a/net/core/pktgen.c
> >> +++ b/net/core/pktgen.c
> >> @@ -177,6 +177,7 @@
> >> #define MPLS_STACK_BOTTOM htonl(0x00000100)
> >> /* Max number of internet mix entries that can be specified in imix_weights. */
> >> #define MAX_IMIX_ENTRIES 20
> >> +#define IMIX_PRECISION 100 /* Precision of IMIX distribution */
> >>
> >> #define func_enter() pr_debug("entering %s\n", __func__);
> >>
> >> @@ -354,6 +355,8 @@ struct pktgen_dev {
> >> /* IMIX */
> >> unsigned int n_imix_entries;
> >> struct imix_pkt imix_entries[MAX_IMIX_ENTRIES];
> >> + /* Maps 0-IMIX_PRECISION range to imix_entry based on probability*/
> >> + __u8 imix_distribution[IMIX_PRECISION];
> >>
> >> /* MPLS */
> >> unsigned int nr_labels; /* Depth of stack, 0 = no MPLS */
> >> @@ -483,6 +486,7 @@ static void pktgen_stop_all_threads(struct pktgen_net *pn);
> >>
> >> static void pktgen_stop(struct pktgen_thread *t);
> >> static void pktgen_clear_counters(struct pktgen_dev *pkt_dev);
> >> +static void fill_imix_distribution(struct pktgen_dev *pkt_dev);
> >
> > Linux next 20210813 tag arm builds failed due to following build errors.
> >
> > Regressions found on arm:
> >
> > - build/gcc-10-ixp4xx_defconfig
> > - build/gcc-10-orion5x_defconfig
> > - build/gcc-10-multi_v5_defconfig
> >
> > net/core/pktgen.c:489:13: warning: 'fill_imix_distribution' used but
> > never defined
> > static void fill_imix_distribution(struct pktgen_dev *pkt_dev);
> > ^~~~~~~~~~~~~~~~~~~~~~
> > ERROR: modpost: "fill_imix_distribution" [net/core/pktgen.ko] undefined!
> > make[2]: *** [scripts/Makefile.modpost:150: modules-only.symvers] Error 1
> > make[2]: *** Deleting file 'modules-only.symvers'
> > make[2]: Target '__modpost' not remade because of errors.
> > make[1]: *** [Makefile:1918: modules] Error 2
> >
> > Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> >
> > Steps to reproduce:
> >
> > # TuxMake is a command line tool and Python library that provides
> > # portable and repeatable Linux kernel builds across a variety of
> > # architectures, toolchains, kernel configurations, and make targets.
> > #
> > # TuxMake supports the concept of runtimes.
> > # See https://docs.tuxmake.org/runtimes/, for that to work it requires
> > # that you install podman or docker on your system.
> > #
> > # To install tuxmake on your system globally:
> > # sudo pip3 install -U tuxmake
> > #
> > # See https://docs.tuxmake.org/ for complete documentation.
> >
> > tuxmake --runtime podman --target-arch arm --toolchain gcc-10
> > --kconfig orion5x_defconfig
> >
> >
> > On Sat, Aug 14, 2021 at 1:13 AM Naresh Kamboju
> > <naresh.kamboju@xxxxxxxxxx> wrote:
> >>
> >> On Wed, 11 Aug 2021 at 00:32, Nicholas Richardson
> >> <richardsonnick@xxxxxxxxxx> wrote:
> >>>
> >>> From: Nick Richardson <richardsonnick@xxxxxxxxxx>
> >>>
> >>> In order to represent the distribution of imix packet sizes, a
> >>> pre-computed data structure is used. It features 100 (IMIX_PRECISION)
> >>> "bins". Contiguous ranges of these bins represent the respective
> >>> packet size of each imix entry. This is done to avoid the overhead of
> >>> selecting the correct imix packet size based on the corresponding weights.
> >>>
> >>> Example:
> >>> imix_weights 40,7 576,4 1500,1
> >>> total_weight = 7 + 4 + 1 = 12
> >>>
> >>> pkt_size 40 occurs 7/total_weight = 58% of the time
> >>> pkt_size 576 occurs 4/total_weight = 33% of the time
> >>> pkt_size 1500 occurs 1/total_weight = 9% of the time
> >>>
> >>> We generate a random number between 0-100 and select the corresponding
> >>> packet size based on the specified weights.
> >>> Eg. random number = 358723895 % 100 = 65
> >>> Selects the packet size corresponding to index:65 in the pre-computed
> >>> imix_distribution array.
> >>> An example of the pre-computed array is below:
> >>>
> >>> The imix_distribution will look like the following:
> >>> 0 -> 0 (index of imix_entry.size == 40)
> >>> 1 -> 0 (index of imix_entry.size == 40)
> >>> 2 -> 0 (index of imix_entry.size == 40)
> >>> [...] -> 0 (index of imix_entry.size == 40)
> >>> 57 -> 0 (index of imix_entry.size == 40)
> >>> 58 -> 1 (index of imix_entry.size == 576)
> >>> [...] -> 1 (index of imix_entry.size == 576)
> >>> 90 -> 1 (index of imix_entry.size == 576)
> >>> 91 -> 2 (index of imix_entry.size == 1500)
> >>> [...] -> 2 (index of imix_entry.size == 1500)
> >>> 99 -> 2 (index of imix_entry.size == 1500)
> >>>
> >>> Create and use "bin" representation of the imix distribution.
> >>>
> >>> Signed-off-by: Nick Richardson <richardsonnick@xxxxxxxxxx>
> >>> ---
> >>> net/core/pktgen.c | 41 +++++++++++++++++++++++++++++++++++++++++
> >>> 1 file changed, 41 insertions(+)
> >>>
> >>> diff --git a/net/core/pktgen.c b/net/core/pktgen.c
> >>> index a7e45eaccef7..ac1de15000e2 100644
> >>> --- a/net/core/pktgen.c
> >>> +++ b/net/core/pktgen.c
> >>> @@ -177,6 +177,7 @@
> >>> #define MPLS_STACK_BOTTOM htonl(0x00000100)
> >>> /* Max number of internet mix entries that can be specified in imix_weights. */
> >>> #define MAX_IMIX_ENTRIES 20
> >>> +#define IMIX_PRECISION 100 /* Precision of IMIX distribution */
> >>>
> >>> #define func_enter() pr_debug("entering %s\n", __func__);
> >>>
> >>> @@ -354,6 +355,8 @@ struct pktgen_dev {
> >>> /* IMIX */
> >>> unsigned int n_imix_entries;
> >>> struct imix_pkt imix_entries[MAX_IMIX_ENTRIES];
> >>> + /* Maps 0-IMIX_PRECISION range to imix_entry based on probability*/
> >>> + __u8 imix_distribution[IMIX_PRECISION];
> >>>
> >>> /* MPLS */
> >>> unsigned int nr_labels; /* Depth of stack, 0 = no MPLS */
> >>> @@ -483,6 +486,7 @@ static void pktgen_stop_all_threads(struct pktgen_net *pn);
> >>>
> >>> static void pktgen_stop(struct pktgen_thread *t);
> >>> static void pktgen_clear_counters(struct pktgen_dev *pkt_dev);
> >>> +static void fill_imix_distribution(struct pktgen_dev *pkt_dev);
> >>
> >> Linux next 20210813 tag arm builds failed due to following build errors.
> >>
> >> Regressions found on arm:
> >>
> >> - build/gcc-10-ixp4xx_defconfig
> >> - build/gcc-10-orion5x_defconfig
> >> - build/gcc-10-multi_v5_defconfig
> >>
> >> net/core/pktgen.c:489:13: warning: 'fill_imix_distribution' used but
> >> never defined
> >> static void fill_imix_distribution(struct pktgen_dev *pkt_dev);
> >> ^~~~~~~~~~~~~~~~~~~~~~
> >> ERROR: modpost: "fill_imix_distribution" [net/core/pktgen.ko] undefined!
> >> make[2]: *** [scripts/Makefile.modpost:150: modules-only.symvers] Error 1
> >> make[2]: *** Deleting file 'modules-only.symvers'
> >> make[2]: Target '__modpost' not remade because of errors.
> >> make[1]: *** [Makefile:1918: modules] Error 2
> >>
> >> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> >>
> >> Steps to reproduce:
> >>
> >> # TuxMake is a command line tool and Python library that provides
> >> # portable and repeatable Linux kernel builds across a variety of
> >> # architectures, toolchains, kernel configurations, and make targets.
> >> #
> >> # TuxMake supports the concept of runtimes.
> >> # See https://docs.tuxmake.org/runtimes/, for that to work it requires
> >> # that you install podman or docker on your system.
> >> #
> >> # To install tuxmake on your system globally:
> >> # sudo pip3 install -U tuxmake
> >> #
> >> # See https://docs.tuxmake.org/ for complete documentation.
> >>
> >> tuxmake --runtime podman --target-arch arm --toolchain gcc-10
> >> --kconfig orion5x_defconfig
> >>
> >> --
> >> Linaro LKFT
> >> https://lkft.linaro.org
> >
> > Thanks for the reply Naresh. Do you have any ideas on how to resolve
> > this error? Pktgen already defines a couple of function prototypes
> > before they are declared and that seems to be the cause of this error
> > message.
>
> The problem is that you declare and use fill_imix_distribution()
> unconditionally in the file but fill_imix_distribution() is only defined
> if CONFIG_XFRM is set, resulting in this error if CONFIG_XFRM is not set.
>
> Should fill_imix_distribution() be moved out of that block or does it
> truly depend on CONFIG_XFRM? If it does, should the use of
> fill_imix_distribution() be guarded by CONFIG_XFRM as well?
>
> Cheers,
> Nathan

Good catch, thanks. Fixed in v3.

Next message: Nathan Chancellor: "[PATCH] scsi: st: Add missing break in switch statement in st_ioctl()"
Previous message: Nicholas Richardson: "[PATCH v3 3/3] pktgen: Add output for imix results"
In reply to: Nathan Chancellor: "Re: [PATCH v2 2/3] pktgen: Add imix distribution bins"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]