From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5668353978D; Tue, 22 Sep 2026 11:10:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790075412; cv=none; b=XSdzl9c+R1S8d/1veYu43HMvax7qw+TKKn39Y1bEkcyCETPoqjspBY7iy1VgvpCNl7ckWFrdpgpztNVyKYWsKihYUY1IT3xzSQ2iqUE1+rSo47KiFJTVdd1JP30/ClQHggfvxUlYmkv3xMPndO7/mUjwcNdlnyYymf42ok9Y++8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790075412; c=relaxed/simple; bh=DZgZvrw/+5D9TnhHWr+3HmfmfML+adpHNyCbQvC9eK8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WmdCvGs2UecZaW5IjkRJUJTWRAQuzPCojmm/SzDcmAYED7oPsjSlGZrFwokL4SnTsnM3h97qw8iFgKkNhMoANi5+Jux60IZZIg+3oOyIcN71rqYYz+ICmcOZEBC+O4WPkxv0aem6aHPocrNciIAhRG6eV6egh4ej2i8fPqWjsn4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=UDxSqGlv; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="UDxSqGlv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=HOgFPgD4DC03gxQwx5pH0/2BpK5RRoQfCZnIS6bmzGY=; t=1790075409; x=1791285009; b=UDxSqGlv6BY/ymWwVr7WGPnuWYZSoxl1CU+dPcm5WG7h6lY O5dh2jkghO1QJ76m2uSwEdSo5u9eq9foGwAU4V4gd0pzIaxddSLGZDO3tXBBl6J7YgEJ8bM8AOY6g GKOfICZzEjRDfYd27+YMTuKel5awzNjMyI8sYO9APn4w0PgK3GpZM1B/JeEK1YxiG6ZaoKDrpxrXT 3+ch1/6Q2d5mIo04XcrEReuvrTisevpXWVv2VYyCE5XbKFtenayGYn2x2ozpWz9aVvnckzaqEa3YM pYycXoh168dUFsVYHIbcdOL5k98Si4lthmcR2Rp0EUxUtk8YRr5RV/xh8/RyyHPg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1x8yNv-00000006qo8-2qmM; Tue, 22 Sep 2026 13:10:03 +0200 From: Johannes Berg To: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Ilya Maximets , Matthieu Baerts , Aaron Conole , Eelco Chaudron , dev@openvswitch.org, Adrian Moreno , Antoine Tenart , Johannes Berg Subject: [PATCH v7 3/4] net: dropreason: use new __print_sym() in tracing Date: Tue, 22 Sep 2026 13:08:42 +0200 Message-ID: <20260922110955.363677-9-johannes@sipsolutions.net> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260922110955.363677-6-johannes@sipsolutions.net> References: <20260922110955.363677-6-johannes@sipsolutions.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Johannes Berg The __print_symbolic() could only ever print the core drop reasons, since that's the way the infrastructure works. Now that we have __print_sym() with all the advantages mentioned in that commit, convert to that and get all the drop reasons from all subsystems. As we already have a list of them, that's really easy. This is a little bit of .text (~100 bytes in my build) and saves a lot of .data (~17k). Signed-off-by: Johannes Berg --- v7: update the selftest accordingly --- include/net/dropreason.h | 5 +++ include/trace/events/skb.h | 13 ++---- net/core/skbuff.c | 43 +++++++++++++++++++ .../selftests/net/openvswitch/openvswitch.sh | 17 ++------ 4 files changed, 55 insertions(+), 23 deletions(-) diff --git a/include/net/dropreason.h b/include/net/dropreason.h index 1df60645fb27..dc4a60130c09 100644 --- a/include/net/dropreason.h +++ b/include/net/dropreason.h @@ -42,6 +42,11 @@ struct drop_reason_list { extern const struct drop_reason_list __rcu * drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM]; +#ifdef CONFIG_TRACEPOINTS +const char *drop_reason_lookup(unsigned long long value); +void drop_reason_show(struct seq_file *m); +#endif + void drop_reasons_register_subsys(enum skb_drop_reason_subsys subsys, const struct drop_reason_list *list); void drop_reasons_unregister_subsys(enum skb_drop_reason_subsys subsys); diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 2945aa7fe9a7..991bf172a6ea 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -8,15 +8,9 @@ #include #include #include +#include -#undef FN -#define FN(reason) TRACE_DEFINE_ENUM(SKB_DROP_REASON_##reason); -DEFINE_DROP_REASON(FN, FN) - -#undef FN -#undef FNe -#define FN(reason) { SKB_DROP_REASON_##reason, #reason }, -#define FNe(reason) { SKB_DROP_REASON_##reason, #reason } +TRACE_DEFINE_SYM_FNS(drop_reason, drop_reason_lookup, drop_reason_show); /* * Tracepoint for free an sk_buff: @@ -47,8 +41,7 @@ TRACE_EVENT(kfree_skb, TP_printk("skbaddr=%p rx_sk=%p protocol=%u location=%pS reason: %s", __entry->skbaddr, __entry->rx_sk, __entry->protocol, __entry->location, - __print_symbolic(__entry->reason, - DEFINE_DROP_REASON(FN, FNe))) + __print_sym(__entry->reason, drop_reason)) ); #undef FN diff --git a/net/core/skbuff.c b/net/core/skbuff.c index dbbe10277d51..8c8f7a05dea4 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -154,6 +154,49 @@ drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM] = { }; EXPORT_SYMBOL(drop_reasons_by_subsys); +#ifdef CONFIG_TRACEPOINTS +const char *drop_reason_lookup(unsigned long long value) +{ + unsigned long long subsys_id = value >> SKB_DROP_REASON_SUBSYS_SHIFT; + u32 reason = value & ~SKB_DROP_REASON_SUBSYS_MASK; + const struct drop_reason_list *subsys; + + if (subsys_id >= SKB_DROP_REASON_SUBSYS_NUM) + return NULL; + + subsys = rcu_dereference(drop_reasons_by_subsys[subsys_id]); + if (!subsys) + return NULL; + if (reason >= subsys->n_reasons) + return NULL; + return subsys->reasons[reason]; +} + +void drop_reason_show(struct seq_file *m) +{ + u32 subsys_id; + + rcu_read_lock(); + for (subsys_id = 0; subsys_id < SKB_DROP_REASON_SUBSYS_NUM; subsys_id++) { + const struct drop_reason_list *subsys; + u32 i; + + subsys = rcu_dereference(drop_reasons_by_subsys[subsys_id]); + if (!subsys) + continue; + + for (i = 0; i < subsys->n_reasons; i++) { + if (!subsys->reasons[i]) + continue; + seq_printf(m, ", { %u, \"%s\" }", + (subsys_id << SKB_DROP_REASON_SUBSYS_SHIFT) | i, + subsys->reasons[i]); + } + } + rcu_read_unlock(); +} +#endif + /** * drop_reasons_register_subsys - register another drop reason subsystem * @subsys: the subsystem to register, must not be the core diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh index a31f7fb6882d..9b8edfcd2d1a 100755 --- a/tools/testing/selftests/net/openvswitch/openvswitch.sh +++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh @@ -234,7 +234,7 @@ ovs_drop_reason_count() local reason=$1 local perf_output=`perf script -i ${ovs_dir}/perf.data -F trace:event,trace` - local pattern="skb:kfree_skb:.*reason: $reason" + local pattern="skb:kfree_skb:.*reason: $reason$" return `echo "$perf_output" | grep "$pattern" | wc -l` } @@ -790,15 +790,6 @@ test_psample() { # - drop packets and verify the right drop reason is reported test_drop_reason() { which perf >/dev/null 2>&1 || return $ksft_skip - which pahole >/dev/null 2>&1 || return $ksft_skip - - ovs_drop_subsys=$(pahole -C skb_drop_reason_subsys | - awk '/OPENVSWITCH/ { print $3; }' | - tr -d ,) - if [ -z "$ovs_drop_subsys" ]; then - info "failed to get OVS drop subsys ID" - return $ksft_skip - fi sbx_add "test_drop_reason" || return $? @@ -842,7 +833,7 @@ test_drop_reason() { "in_port(2),eth(),eth_type(0x0800),ipv4(src=172.31.110.20,proto=1),icmp()" 'drop' ovs_drop_record_and_run "test_drop_reason" ip netns exec client ping -c 2 172.31.110.20 - ovs_drop_reason_count 0x${ovs_drop_subsys}0001 # OVS_DROP_FLOW_ACTION + ovs_drop_reason_count OVS_DROP_LAST_ACTION if [[ "$?" -ne "2" ]]; then info "Did not detect expected drops: $?" return 1 @@ -859,7 +850,7 @@ test_drop_reason() { ovs_drop_record_and_run \ "test_drop_reason" ip netns exec client nc -i 1 -zuv 172.31.110.20 6000 - ovs_drop_reason_count 0x${ovs_drop_subsys}0004 # OVS_DROP_EXPLICIT_ACTION_ERROR + ovs_drop_reason_count OVS_DROP_EXPLICIT_WITH_ERROR if [[ "$?" -ne "1" ]]; then info "Did not detect expected explicit error drops: $?" return 1 @@ -867,7 +858,7 @@ test_drop_reason() { ovs_drop_record_and_run \ "test_drop_reason" ip netns exec client nc -i 1 -zuv 172.31.110.20 7000 - ovs_drop_reason_count 0x${ovs_drop_subsys}0003 # OVS_DROP_EXPLICIT_ACTION + ovs_drop_reason_count OVS_DROP_EXPLICIT if [[ "$?" -ne "1" ]]; then info "Did not detect expected explicit drops: $?" return 1 -- 2.55.0