From nobody Tue Sep 9 21:36:16 2025 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.3]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F28991EB193; Sat, 6 Sep 2025 17:30:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757179849; cv=none; b=On8Dl42LLeqZdYwkxLt/k+B6o5mUb9i+TLxi5nmIjbEvsg72VMStFAADfvm3clZIZK1IOAXX56TnwYMaB1iP5f0/1Ogr779PXlqXlIiQFDb/Oilj69Bn+PpGyJjRQ8ixd7tzcxdnyX4qJ3zl3tkzruPyEvJGL/u910luKzv39SE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757179849; c=relaxed/simple; bh=k/e+GxLzaLWHXW4ybilZi/DyVV97aJCPpbq+l5+E5pM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OIgrA2L7yjDvFZ8HKGorhT3t56f9ba96FkEvzxfw4iHe8UhqlrHMWca5+QPj7XYMIvht7RBpGLzZ2dnA2xaiedPL5CeDdNIo08b2hLu0WXJ34xO1s+a6hI/UY5aWLJrSBKID+XNC0E1SXNe3kJZW0zkDPXxF+W/6GHcXUwg4lNk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=DDL+Ec0w; arc=none smtp.client-ip=117.135.210.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="DDL+Ec0w" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=JJ aR7eeM4R1xw7uwZoMzi6TmSyd6BYr9d5jerFk/sIU=; b=DDL+Ec0wWWOGi0407M YZnQOwGRQHs7YJyvTm545MPjwoGJ4Ol8cv2gw7sph7+Hj5wLSw5PHJQOVRC/Efe2 B9xLPNjqlFmq1sPznKRWp7xnDvs/F5UwUtrsKZHrn9nE5Bu1gSC4CszoDE25oxY8 qk4MXTZ3sCNyN57eVedbO6new= Received: from zhaoxin-MS-7E12.. (unknown []) by gzga-smtp-mtada-g0-4 (Coremail) with SMTP id _____wD3f+Wbb7xoubfqGQ--.36512S3; Sun, 07 Sep 2025 01:30:07 +0800 (CST) From: Xin Zhao To: willemdebruijn.kernel@gmail.com, kerneljasonxing@gmail.com, edumazet@google.com, ferenc@fejes.dev Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Xin Zhao Subject: [PATCH net-next v11 1/2] net: af_packet: remove last_kactive_blk_num field Date: Sun, 7 Sep 2025 01:30:00 +0800 Message-Id: <20250906173001.3656356-2-jackzxcui1989@163.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250906173001.3656356-1-jackzxcui1989@163.com> References: <20250906173001.3656356-1-jackzxcui1989@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wD3f+Wbb7xoubfqGQ--.36512S3 X-Coremail-Antispam: 1Uf129KBjvJXoWxurWUJrWxAFWkXFW5Ar1kZrb_yoWruF4xpF WYkw13Gw1DGr42gw4xZwnrZr15Ww45XFyUGr98Jw4fAasxJryaya9F9ry7WFyFyFZ3Zay2 qrs5t345Cw1DJrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0z_E_MUUUUUU= X-CM-SenderInfo: pmdfy650fxxiqzyzqiywtou0bp/1tbiJQ3ACmi8a+ReEgABs0 Content-Type: text/plain; charset="utf-8" kactive_blk_num (K) is only incremented on block close. In timer callback prb_retire_rx_blk_timer_expired, except delete_blk_timer is true, last_kactive_blk_num (L) is set to match kactive_blk_num (K) in all cases. L is also set to match K in prb_open_block. The only case K not equal to L is when scheduled by tpacket_rcv and K is just incremented on block close but no new block could be opened, so that it does not call prb_open_block in prb_dispatch_next_block. This patch modifies the prb_retire_rx_blk_timer_expired function by simply=20 removing the check for L =3D=3D K. This patch just provides another checkpo= int to thaw the might-be-frozen block in any case. It doesn't have any effect because __packet_lookup_frame_in_block() has the same logic and does it again without this patch when detecting the ring is frozen. The patch only advances checking the status of the ring. Suggested-by: Willem de Bruijn Reviewed-by: Willem de Bruijn Reviewed-by: Jason Xing Link: https://lore.kernel.org/all/20250831100822.1238795-1-jackzxcui1989@16= 3.com/ Signed-off-by: Xin Zhao --- net/packet/af_packet.c | 60 ++++++++++++++++++++---------------------- net/packet/internal.h | 6 ----- 2 files changed, 28 insertions(+), 38 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index a7017d7f0..d4eb4a4fe 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -669,7 +669,6 @@ static void init_prb_bdqc(struct packet_sock *po, p1->knum_blocks =3D req_u->req3.tp_block_nr; p1->hdrlen =3D po->tp_hdrlen; p1->version =3D po->tp_version; - p1->last_kactive_blk_num =3D 0; po->stats.stats3.tp_freeze_q_cnt =3D 0; if (req_u->req3.tp_retire_blk_tov) p1->retire_blk_tov =3D req_u->req3.tp_retire_blk_tov; @@ -693,7 +692,6 @@ static void _prb_refresh_rx_retire_blk_timer(struct tpa= cket_kbdq_core *pkc) { mod_timer(&pkc->retire_blk_timer, jiffies + pkc->tov_in_jiffies); - pkc->last_kactive_blk_num =3D pkc->kactive_blk_num; } =20 /* @@ -750,38 +748,36 @@ static void prb_retire_rx_blk_timer_expired(struct ti= mer_list *t) write_unlock(&pkc->blk_fill_in_prog_lock); } =20 - if (pkc->last_kactive_blk_num =3D=3D pkc->kactive_blk_num) { - if (!frozen) { - if (!BLOCK_NUM_PKTS(pbd)) { - /* An empty block. Just refresh the timer. */ - goto refresh_timer; - } - prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); - if (!prb_dispatch_next_block(pkc, po)) - goto refresh_timer; - else - goto out; + if (!frozen) { + if (!BLOCK_NUM_PKTS(pbd)) { + /* An empty block. Just refresh the timer. */ + goto refresh_timer; + } + prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); + if (!prb_dispatch_next_block(pkc, po)) + goto refresh_timer; + else + goto out; + } else { + /* Case 1. Queue was frozen because user-space was + * lagging behind. + */ + if (prb_curr_blk_in_use(pbd)) { + /* + * Ok, user-space is still behind. + * So just refresh the timer. + */ + goto refresh_timer; } else { - /* Case 1. Queue was frozen because user-space was - * lagging behind. + /* Case 2. queue was frozen,user-space caught up, + * now the link went idle && the timer fired. + * We don't have a block to close.So we open this + * block and restart the timer. + * opening a block thaws the queue,restarts timer + * Thawing/timer-refresh is a side effect. */ - if (prb_curr_blk_in_use(pbd)) { - /* - * Ok, user-space is still behind. - * So just refresh the timer. - */ - goto refresh_timer; - } else { - /* Case 2. queue was frozen,user-space caught up, - * now the link went idle && the timer fired. - * We don't have a block to close.So we open this - * block and restart the timer. - * opening a block thaws the queue,restarts timer - * Thawing/timer-refresh is a side effect. - */ - prb_open_block(pkc, pbd); - goto out; - } + prb_open_block(pkc, pbd); + goto out; } } =20 diff --git a/net/packet/internal.h b/net/packet/internal.h index 1e743d031..d367b9f93 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -24,12 +24,6 @@ struct tpacket_kbdq_core { unsigned short kactive_blk_num; unsigned short blk_sizeof_priv; =20 - /* last_kactive_blk_num: - * trick to see if user-space has caught up - * in order to avoid refreshing timer when every single pkt arrives. - */ - unsigned short last_kactive_blk_num; - char *pkblk_start; char *pkblk_end; int kblk_size; --=20 2.34.1