From patchwork Thu Jun 23 04:34:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 12891743 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2ED3CCA481 for ; Thu, 23 Jun 2022 04:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231220AbiFWEkn (ORCPT ); Thu, 23 Jun 2022 00:40:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347294AbiFWEe5 (ORCPT ); Thu, 23 Jun 2022 00:34:57 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3F0030F71 for ; Wed, 22 Jun 2022 21:34:56 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id h82-20020a25d055000000b00668b6a4ee32so14237148ybg.3 for ; Wed, 22 Jun 2022 21:34:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=QSDlsc5UXnSdWWDeGFSK6eE1vvN88jA3TNSNM9+wjBE=; b=l1pTu7iFtJKWY5F41oGRuTA68hYV6iPjaIsN2nKjA4GcpU3fIWYuygJs2Mi7atj7fm 9FyGQL1evYZ/zDpMBd5Z72cgHE4Vjr6CGsP/5wXGMIZmTTliAI3fNwujTNM49OONGnfE DXXXjLDXaEAVZRHkjqOhrCDFoJnQPGHD11MxxLXOarjWNLayDwAebedlmHD8ChuPGWso H35obBeiMtUkYTt4/eP5W+DR9VHkG+31DecCOTJgVzn0NYSsnYZa1/jD7q0il4l8HlzJ Do6PKWin9vKUTYzmWUVLHiOWTvcdurHcT9ov0ChTRalP1wMVrA2RnImHzHl9ch36OFOQ V81g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=QSDlsc5UXnSdWWDeGFSK6eE1vvN88jA3TNSNM9+wjBE=; b=Z0D4tCOg5yCHO60vtxkUAAcohU8WUxLCGJC7A5mieiTSKt2t61+lcx2beePcliAzSH Y0MU1wuZN9mlGFw4Y6TvrP6othtNXznYNnMQg52m5x52TiFG/rSqPCzI3luqiFpNnTaL CwTeLKbLk8XhFg4+65mN5ONIJ61w7dAM6uNGHwv4cZQqlWAwMv9XYCFCy/eeW+jc5PCw 9xlXIgN9TyDzl4hTqXbuZ7ueJD2EPH95in07J4c+jytxBFHtVQdJlUS4T0dSA7omiPs+ ITZ2s3VpUbESuCKSRGkTlv/8JpQkCYnDZHS5gN/I6Mb8IrX/gXNuQERzYuwyBYxvI0lY sjuQ== X-Gm-Message-State: AJIora8oyhOTPB7DMaUlamwAas7Wtt1ektiApKIZTt8LAydYc9pdXvi8 C13m4OqynXcmB6NtlFQd/Niog4NjBwGqNQ== X-Google-Smtp-Source: AGRyM1sexi7Ti5BBJvAdDldD/cgbS692/J5asgjF50EUYD2vCbTyL+SX8uGlo3Mo46xBQO7yA11f+ZxWg/sN4g== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a25:2309:0:b0:668:a570:f69a with SMTP id j9-20020a252309000000b00668a570f69amr7701695ybj.554.1655958895945; Wed, 22 Jun 2022 21:34:55 -0700 (PDT) Date: Thu, 23 Jun 2022 04:34:30 +0000 Message-Id: <20220623043449.1217288-1-edumazet@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.37.0.rc0.104.g0611611a94-goog Subject: [PATCH v2 net-next 00/19] ipmr: get rid of rwlocks From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org We need to get rid of rwlocks in networking stacks, if read_lock() is (ab)used from softirq context. As discussed recently [1], rwlock are unfair by design in this case, and writers can starve and trigger soft lockups. This series convert ipmr code (both IPv4 and IPv6 families) to RCU and spinlocks. [1] https://lkml.org/lkml/2022/6/17/272 v2: fixed two typos, and resent because patch 19/19 did not make it to patchwork. Eric Dumazet (19): ip6mr: do not get a device reference in pim6_rcv() ipmr: add rcu protection over (struct vif_device)->dev ipmr: change igmpmsg_netlink_event() prototype ipmr: ipmr_cache_report() changes ipmr: do not acquire mrt_lock in __pim_rcv() ipmr: do not acquire mrt_lock in ioctl(SIOCGETVIFCNT) ipmr: do not acquire mrt_lock before calling ipmr_cache_unresolved() ipmr: do not acquire mrt_lock while calling ip_mr_forward() ipmr: do not acquire mrt_lock in ipmr_get_route() ip6mr: ip6mr_cache_report() changes ip6mr: do not acquire mrt_lock in pim6_rcv() ip6mr: do not acquire mrt_lock in ioctl(SIOCGETMIFCNT_IN6) ip6mr: do not acquire mrt_lock before calling ip6mr_cache_unresolved ip6mr: do not acquire mrt_lock while calling ip6_mr_forward() ip6mr: switch ip6mr_get_route() to rcu_read_lock() ipmr: adopt rcu_read_lock() in mr_dump() ipmr: convert /proc handlers to rcu_read_lock() ipmr: convert mrt_lock to a spinlock ip6mr: convert mrt_lock to a spinlock include/linux/mroute_base.h | 15 ++- net/ipv4/ipmr.c | 215 +++++++++++++++++++----------------- net/ipv4/ipmr_base.c | 53 +++++---- net/ipv6/ip6mr.c | 202 ++++++++++++++++----------------- 4 files changed, 255 insertions(+), 230 deletions(-)