Skip site navigation (1)Skip section navigation (2) 
Date:      Mon, 20 Nov 2017 04:32:01 +0000 (UTC)
From:      Justin Hibbits <jhibbits@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r326004 - head/sys/dev/dpaa
Message-ID:  <201711200432.vAK4W1OE047727@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help 
Author: jhibbits
Date: Mon Nov 20 04:32:01 2017
New Revision: 326004
URL: https://svnweb.freebsd.org/changeset/base/326004

Log:
  Eliminate 1 XX_VirtToPhys() and 2 XX_PhysToVirt() calls from if_dtsec(4)
  
  XX_VirtToPhys(), by way of pmap_kextract(), is an expensive operation.
  Profiling via dtrace during a series of iperf tests I found 16111 / 30432
  stack frames were located in mmu_booke_kextract(), so eliminating this
  expensive call should improve performance slightly.  XX_PhysToVirt() is not
  as expensive, but redundant calls in this context is wasteful.

Modified:
  head/sys/dev/dpaa/if_dtsec_rm.c

Modified: head/sys/dev/dpaa/if_dtsec_rm.c
==============================================================================
--- head/sys/dev/dpaa/if_dtsec_rm.c	Mon Nov 20 03:40:50 2017	(r326003)
+++ head/sys/dev/dpaa/if_dtsec_rm.c	Mon Nov 20 04:32:01 2017	(r326004)
@@ -358,10 +358,12 @@ dtsec_rm_fqr_rx_callback(t_Handle app, t_Handle fqr, t
 {
 	struct dtsec_softc *sc;
 	struct mbuf *m;
+	void *frame_va;
 
 	m = NULL;
 	sc = app;
 
+	frame_va = DPAA_FD_GET_ADDR(frame);
 	KASSERT(DPAA_FD_GET_FORMAT(frame) == e_DPAA_FD_FORMAT_TYPE_SHORT_SBSF,
 	    ("%s(): Got unsupported frame format 0x%02X!", __func__,
 	    DPAA_FD_GET_FORMAT(frame)));
@@ -379,8 +381,8 @@ dtsec_rm_fqr_rx_callback(t_Handle app, t_Handle fqr, t
 	if (m == NULL)
 		goto err;
 
-	m_extadd(m, DPAA_FD_GET_ADDR(frame), FM_PORT_BUFFER_SIZE,
-	    dtsec_rm_fqr_mext_free, DPAA_FD_GET_ADDR(frame), sc, 0,
+	m_extadd(m, frame_va, FM_PORT_BUFFER_SIZE,
+	    dtsec_rm_fqr_mext_free, frame_va, sc, 0,
 	    EXT_NET_DRV);
 
 	m->m_pkthdr.rcvif = sc->sc_ifnet;
@@ -392,7 +394,7 @@ dtsec_rm_fqr_rx_callback(t_Handle app, t_Handle fqr, t
 	return (e_RX_STORE_RESPONSE_CONTINUE);
 
 err:
-	bman_put_buffer(sc->sc_rx_pool, DPAA_FD_GET_ADDR(frame));
+	bman_put_buffer(sc->sc_rx_pool, frame_va);
 	if (m != NULL)
 		m_freem(m);
 
@@ -545,7 +547,6 @@ dtsec_rm_if_start_locked(struct dtsec_softc *sc)
 	unsigned int qlen, i;
 	struct mbuf *m0, *m;
 	vm_offset_t vaddr;
-	vm_paddr_t paddr;
 	t_DpaaFD fd;
 
 	DTSEC_LOCK_ASSERT(sc);
@@ -602,8 +603,7 @@ dtsec_rm_if_start_locked(struct dtsec_softc *sc)
 			dsize = m->m_len;
 			vaddr = (vm_offset_t)m->m_data;
 			while (dsize > 0 && i < DPAA_NUM_OF_SG_TABLE_ENTRY) {
-				paddr = XX_VirtToPhys((void *)vaddr);
-				ssize = PAGE_SIZE - (paddr & PAGE_MASK);
+				ssize = PAGE_SIZE - (vaddr & PAGE_MASK);
 				if (m->m_len < ssize)
 					ssize = m->m_len;

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201711200432.vAK4W1OE047727>