From e67e4bd3b3715e317b046dbb93ca04766d990ed8 Mon Sep 17 00:00:00 2001 From: Coiby Xu Date: Fri, 25 Nov 2022 09:43:05 +0800 Subject: [PATCH] Reduce kdump memory consumption by only installing needed NIC drivers Resolves: bz1958587 Upstream: Fedora Conflict: 1. RHEL8's mkdumprd has different dracut_args from upstream's. 2. RHEL8's kdump_install_net is different from upstream's and we should install needed NIC drivers in the end. commit a65dde2d1083a57824aecd1840dea417c98c553d Author: Coiby Xu Date: Thu May 19 11:39:25 2022 +0800 Reduce kdump memory consumption by only installing needed NIC drivers Even after having asked NM to stop managing a unneeded NIC, a NIC driver may still waste memory. For example, mlx5_core uses a substantial amount of memory during driver initialization, ======== Report format module_summary: ======== Module mlx5_core using 350.2MB (89650 pages), peak allocation 367.4MB (94056 pages) Module squashfs using 13.1MB (3360 pages), peak allocation 13.1MB (3360 pages) Module overlay using 2.1MB (550 pages), peak allocation 2.2MB (555 pages) Module dns_resolver using 0.9MB (219 pages), peak allocation 5.2MB (1338 pages) Module mlxfw using 0.7MB (172 pages), peak allocation 5.3MB (1349 pages) ======== Report format module_summary END ======== ======== Report format module_top: ======== Top stack usage of module mlx5_core: (null) Pages: 89650 (peak: 94056) ret_from_fork (0xffffda088b4165f8) Pages: 60007 (peak: 60007) kthread (0xffffda088b4bd7e4) Pages: 60007 (peak: 60007) worker_thread (0xffffda088b4b48d0) Pages: 60007 (peak: 60007) process_one_work (0xffffda088b4b3f40) Pages: 60007 (peak: 60007) work_for_cpu_fn (0xffffda088b4aef00) Pages: 53906 (peak: 53906) local_pci_probe (0xffffda088b9e1e44) Pages: 53906 (peak: 53906) probe_one mlx5_core (0xffffda084f899cc8) Pages: 53518 (peak: 53518) mlx5_init_one mlx5_core (0xffffda084f8994ac) Pages: 49756 (peak: 49756) mlx5_function_setup.constprop.0 mlx5_core (0xffffda084f899100) Pages: 44434 (eak: 44434) mlx5_satisfy_startup_pages mlx5_core (0xffffda084f8a4f24) Pages: 44434 (peak: 44434) mlx5_function_setup.constprop.0 mlx5_core (0xffffda084f899078) Pages: 5285 (peak: 5285) mlx5_cmd_init mlx5_core (0xffffda084f89e414) Pages: 4818 (peak: 4818) mlx5_alloc_cmd_msg mlx5_core (0xffffda084f89aaa0) Pages: 4403 (peak: 4403) This memory consumption is completely unnecessary when kdump doesn't need this NIC. Only install needed NIC drivers to prevent this kind of waste. Note 1. this patch depends on [1] to ask dracut to not install NIC drivers. 2. "ethtool -i" somehow fails to get the vlan driver 3. team.ko doesn't depend on the team mode drivers so we need to install the team mode drivers manually. [1] https://github.com/dracutdevs/dracut/pull/1789 Signed-off-by: Coiby Xu Reviewed-by: Thomas Haller Reviewed-by: Philipp Rudo Signed-off-by: Coiby Xu --- dracut-module-setup.sh | 31 +++++++++++++++++++++++++++++++ mkdumprd | 2 +- 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 27be84b..c6c8f40 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -347,6 +347,36 @@ EOF rm -f "$_netif_allowlist_nm_conf" } +_get_nic_driver() { + ethtool -i "$1" | sed -n -E "s/driver: (.*)/\1/p" +} + +kdump_install_nic_driver() { + local _netif _driver _drivers + + _drivers=() + + for _netif in $1; do + _driver=$(_get_nic_driver "$_netif") + if [[ -z $_driver ]]; then + derror "Failed to get the driver of $_netif" + exit 1 + fi + + if [[ $_driver == "802.1Q VLAN Support" ]]; then + # ethtool somehow doesn't return the driver name for a VLAN NIC + _driver=8021q + elif [[ $_driver == "team" ]]; then + # install the team mode drivers like team_mode_roundrobin.ko as well + _driver='=drivers/net/team' + fi + + _drivers+=("$_driver") + done + + instmods "${_drivers[@]}" +} + kdump_setup_bridge() { local _netdev=$1 local _brif _dev _mac _kdumpdev @@ -1069,6 +1099,7 @@ install() { _netifs=$(_get_kdump_netifs) if [[ -n "$_netifs" ]]; then kdump_install_nm_netif_allowlist "$_netifs" + kdump_install_nic_driver "$_netifs" fi kdump_install_systemd_conf diff --git a/mkdumprd b/mkdumprd index 43df102..f6438e9 100644 --- a/mkdumprd +++ b/mkdumprd @@ -29,7 +29,7 @@ SAVE_PATH=$(get_save_path) OVERRIDE_RESETTABLE=0 extra_modules="" -dracut_args="--add kdumpbase --quiet --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode strict -o \"plymouth dash resume ifcfg earlykdump\" --compress=xz" +dracut_args="--add kdumpbase --quiet --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode strict --hostonly-nics '' -o \"plymouth dash resume ifcfg earlykdump\" --compress=xz" readonly MKDUMPRD_TMPDIR="$(mktemp -d -t mkdumprd.XXXXXX)" [ -d "$MKDUMPRD_TMPDIR" ] || perror_exit "dracut: mktemp -p -d -t dracut.XXXXXX failed."