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(unknown []) by gzga-smtp-mtada-g1-1 (Coremail) with SMTP id _____wBH7U4YH7RoR1JrFA--.61212S3; Sun, 31 Aug 2025 18:08:35 +0800 (CST) From: Xin Zhao To: willemdebruijn.kernel@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 v10 1/2] net: af_packet: remove last_kactive_blk_num field Date: Sun, 31 Aug 2025 18:08:21 +0800 Message-Id: <20250831100822.1238795-2-jackzxcui1989@163.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250831100822.1238795-1-jackzxcui1989@163.com> References: <20250831100822.1238795-1-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: _____wBH7U4YH7RoR1JrFA--.61212S3 X-Coremail-Antispam: 1Uf129KBjvJXoWxCr1fXFW8tr1rur4kWFWfKrg_yoWrGr43pF W3A343Jw4DGr4agw4xZwnrZr15Ww4rWFy8G3sxJw4fA3s3Aryava9F9Fy7WFyrJrZ3Zay7 Xrs5t345Cr4kJrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0z_F4iUUUUUU= X-CM-SenderInfo: pmdfy650fxxiqzyzqiywtou0bp/1tbiRxG6Cmi0Dcz5bQAAsv Content-Type: text/plain; charset="utf-8" kactive_blk_num (K) is incremented on block close. last_kactive_blk_num (L) is set to match K on block open and each timer. So the only time that they differ is if a block is closed in tpacket_rcv and no new block could be opened. So the origin check L=3D=3DK in timer callback only skip the case 'no new b= lock to open'. If we remove L=3D=3DK check, it will make prb_curr_blk_in_use che= ck earlier, which will not cause any side effect. Signed-off-by: Xin Zhao Reviewed-by: Jason Xing Reviewed-by: Willem de Bruijn Suggested-by: Willem de Bruijn --- 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