tools/testing/selftests/drivers/net/hw/rss_drv.py

Source file repositories/reference/linux-study-clean/tools/testing/selftests/drivers/net/hw/rss_drv.py

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/drivers/net/hw/rss_drv.py
Extension
.py
Size
10849 bytes
Lines
314
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0

"""
Driver-related behavior tests for RSS.
"""

from lib.py import ksft_run, ksft_exit, ksft_eq, ksft_ge
from lib.py import ksft_variants, KsftNamedVariant, KsftSkipEx, ksft_raises
from lib.py import defer, ethtool, CmdExitFailure
from lib.py import EthtoolFamily, NlError
from lib.py import NetDrvEnv


def _is_power_of_two(n):
    return n > 0 and (n & (n - 1)) == 0


def _get_rss(cfg, context=0):
    return ethtool(f"-x {cfg.ifname} context {context}", json=True)[0]


def _test_rss_indir_size(cfg, qcnt, context=0):
    """Test that indirection table size is at least 4x queue count."""
    ethtool(f"-L {cfg.ifname} combined {qcnt}")

    rss = _get_rss(cfg, context=context)
    indir = rss['rss-indirection-table']
    ksft_ge(len(indir), 4 * qcnt, "Table smaller than 4x")
    return len(indir)


def _maybe_create_context(cfg, create_context):
    """ Either create a context and return its ID or return 0 for main ctx """
    if not create_context:
        return 0
    try:
        ctx = cfg.ethnl.rss_create_act({'header': {'dev-index': cfg.ifindex}})
        ctx_id = ctx['context']
        defer(cfg.ethnl.rss_delete_act,
              {'header': {'dev-index': cfg.ifindex}, 'context': ctx_id})
    except NlError:
        raise KsftSkipEx("Device does not support additional RSS contexts")

    return ctx_id


def _require_dynamic_indir_size(cfg, ch_max):
    """Skip if the device does not dynamically size its indirection table."""
    ethtool(f"-X {cfg.ifname} default")
    ethtool(f"-L {cfg.ifname} combined 2")
    small = len(_get_rss(cfg)['rss-indirection-table'])
    ethtool(f"-L {cfg.ifname} combined {ch_max}")
    large = len(_get_rss(cfg)['rss-indirection-table'])

    if small == large:
        raise KsftSkipEx("Device does not dynamically size indirection table")


@ksft_variants([
    KsftNamedVariant("main", False),
    KsftNamedVariant("ctx", True),
])
def indir_size_4x(cfg, create_context):
    """
    Test that the indirection table has at least 4 entries per queue.
    Empirically network-heavy workloads like memcache suffer with the 33%
    imbalance of a 2x indirection table size.
    4x table translates to a 16% imbalance.
    """

Annotation

Implementation Notes