From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from Galois.linutronix.de ([193.142.43.55]:54282 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgKRKyC (ORCPT ); Wed, 18 Nov 2020 05:54:02 -0500 From: Sebastian Andrzej Siewior Subject: [PATCH 1/6] s390/ctcm: Put struct th_header and th_sweep on stack. Date: Wed, 18 Nov 2020 11:53:12 +0100 Message-Id: <20201118105317.605671-2-bigeasy@linutronix.de> In-Reply-To: <20201118105317.605671-1-bigeasy@linutronix.de> References: <20201118105317.605671-1-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable List-ID: To: linux-s390@vger.kernel.org Cc: Julian Wiedmann , Karsten Graul , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Thomas Gleixner , Sebastian Andrzej Siewior The size of struct th_header is 8 byte and the size of struct th_sweep is 16 byte. The memory for is allocated, initialized, used and deallocated a few lines later. It is more efficient to avoid the allocation/free dance and keeping the variable on stack. Especially since the compiler is smart enough to not allocate the memory on stack but assign the values directly. Declare struct th_sweep/th_header on stack and initialize it to zero. Use the local variable instead of the pointer. Signed-off-by: Sebastian Andrzej Siewior --- drivers/s390/net/ctcm_fsms.c | 17 +++++----------- drivers/s390/net/ctcm_main.c | 39 ++++++++---------------------------- drivers/s390/net/ctcm_mpc.c | 21 ++++--------------- 3 files changed, 17 insertions(+), 60 deletions(-) diff --git a/drivers/s390/net/ctcm_fsms.c b/drivers/s390/net/ctcm_fsms.c index 661d2a49bce96..d6592d576d1dd 100644 --- a/drivers/s390/net/ctcm_fsms.c +++ b/drivers/s390/net/ctcm_fsms.c @@ -1220,7 +1220,7 @@ static void ctcmpc_chx_txdone(fsm_instance *fi, int e= vent, void *arg) unsigned long duration; struct sk_buff *peekskb; int rc; - struct th_header *header; + struct th_header header =3D {0, }; struct pdu *p_header; unsigned long done_stamp =3D jiffies; =20 @@ -1303,24 +1303,17 @@ static void ctcmpc_chx_txdone(fsm_instance *fi, int= event, void *arg) /* p_header points to the last one we handled */ if (p_header) p_header->pdu_flag |=3D PDU_LAST; /*Say it's the last one*/ - header =3D kzalloc(TH_HEADER_LENGTH, gfp_type()); - if (!header) { - spin_unlock(&ch->collect_lock); - fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev); - goto done; - } - header->th_ch_flag =3D TH_HAS_PDU; /* Normal data */ + + header.th_ch_flag =3D TH_HAS_PDU; /* Normal data */ ch->th_seq_num++; - header->th_seq_num =3D ch->th_seq_num; + header.th_seq_num =3D ch->th_seq_num; =20 CTCM_PR_DBGDATA("%s: ToVTAM_th_seq=3D %08x\n" , __func__, ch->th_seq_num); =20 - memcpy(skb_push(ch->trans_skb, TH_HEADER_LENGTH), header, + memcpy(skb_push(ch->trans_skb, TH_HEADER_LENGTH), &header, TH_HEADER_LENGTH); /* put the TH on the packet */ =20 - kfree(header); - CTCM_PR_DBGDATA("%s: trans_skb len:%04x \n", __func__, ch->trans_skb->len); CTCM_PR_DBGDATA("%s: up-to-50 bytes of trans_skb " diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c index d06809eac16d3..6c7d6bbd27406 100644 --- a/drivers/s390/net/ctcm_main.c +++ b/drivers/s390/net/ctcm_main.c @@ -599,7 +599,7 @@ static void ctcmpc_send_sweep_req(struct channel *rch) struct net_device *dev =3D rch->netdev; struct ctcm_priv *priv; struct mpc_group *grp; - struct th_sweep *header; + struct th_sweep header =3D { 0, }; struct sk_buff *sweep_skb; struct channel *ch; /* int rc =3D 0; */ @@ -623,24 +623,10 @@ static void ctcmpc_send_sweep_req(struct channel *rch) goto nomem; } =20 - header =3D kmalloc(TH_SWEEP_LENGTH, gfp_type()); + header.th.th_ch_flag =3D TH_SWEEP_REQ; /* 0x0f */ + header.sw.th_last_seq =3D ch->th_seq_num; =20 - if (!header) { - dev_kfree_skb_any(sweep_skb); - /* rc =3D -ENOMEM; */ - goto nomem; - } - - header->th.th_seg =3D 0x00 ; - header->th.th_ch_flag =3D TH_SWEEP_REQ; /* 0x0f */ - header->th.th_blk_flag =3D 0x00; - header->th.th_is_xid =3D 0x00; - header->th.th_seq_num =3D 0x00; - header->sw.th_last_seq =3D ch->th_seq_num; - - skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH); - - kfree(header); + skb_put_data(sweep_skb, &header, TH_SWEEP_LENGTH); =20 netif_trans_update(dev); skb_queue_tail(&ch->sweep_queue, sweep_skb); @@ -666,7 +652,7 @@ static int ctcmpc_transmit_skb(struct channel *ch, stru= ct sk_buff *skb) struct net_device *dev =3D ch->netdev; struct ctcm_priv *priv =3D dev->ml_priv; struct mpc_group *grp =3D priv->mpcg; - struct th_header *header; + struct th_header header =3D { 0, }; struct sk_buff *nskb; int rc =3D 0; int ccw_idx; @@ -768,24 +754,15 @@ static int ctcmpc_transmit_skb(struct channel *ch, st= ruct sk_buff *skb) =20 ch->prof.txlen +=3D skb->len - PDU_HEADER_LENGTH; =20 - header =3D kmalloc(TH_HEADER_LENGTH, gfp_type()); - if (!header) - goto nomem_exit; - - header->th_seg =3D 0x00; - header->th_ch_flag =3D TH_HAS_PDU; /* Normal data */ - header->th_blk_flag =3D 0x00; - header->th_is_xid =3D 0x00; /* Just data here */ + header.th_ch_flag =3D TH_HAS_PDU; /* Normal data */ ch->th_seq_num++; - header->th_seq_num =3D ch->th_seq_num; + header.th_seq_num =3D ch->th_seq_num; =20 CTCM_PR_DBGDATA("%s(%s) ToVTAM_th_seq=3D %08x\n" , __func__, dev->name, ch->th_seq_num); =20 /* put the TH on the packet */ - memcpy(skb_push(skb, TH_HEADER_LENGTH), header, TH_HEADER_LENGTH); - - kfree(header); + memcpy(skb_push(skb, TH_HEADER_LENGTH), &header, TH_HEADER_LENGTH); =20 CTCM_PR_DBGDATA("%s(%s): skb len: %04x\n - pdu header and data for " "up to 32 bytes sent to vtam:\n", diff --git a/drivers/s390/net/ctcm_mpc.c b/drivers/s390/net/ctcm_mpc.c index 85a1a4533cbeb..04a51cc89e74c 100644 --- a/drivers/s390/net/ctcm_mpc.c +++ b/drivers/s390/net/ctcm_mpc.c @@ -641,7 +641,7 @@ static void ctcmpc_send_sweep_resp(struct channel *rch) struct net_device *dev =3D rch->netdev; struct ctcm_priv *priv =3D dev->ml_priv; struct mpc_group *grp =3D priv->mpcg; - struct th_sweep *header; + struct th_sweep header =3D { 0, }; struct sk_buff *sweep_skb; struct channel *ch =3D priv->channel[CTCM_WRITE]; =20 @@ -655,23 +655,10 @@ static void ctcmpc_send_sweep_resp(struct channel *rc= h) goto done; } =20 - header =3D kmalloc(sizeof(struct th_sweep), gfp_type()); + header.th.th_ch_flag =3D TH_SWEEP_RESP; + header.sw.th_last_seq =3D ch->th_seq_num; =20 - if (!header) { - dev_kfree_skb_any(sweep_skb); - goto done; - } - - header->th.th_seg =3D 0x00 ; - header->th.th_ch_flag =3D TH_SWEEP_RESP; - header->th.th_blk_flag =3D 0x00; - header->th.th_is_xid =3D 0x00; - header->th.th_seq_num =3D 0x00; - header->sw.th_last_seq =3D ch->th_seq_num; - - skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH); - - kfree(header); + skb_put_data(sweep_skb, &header, TH_SWEEP_LENGTH); =20 netif_trans_update(dev); skb_queue_tail(&ch->sweep_queue, sweep_skb); --=20 2.29.2