Date: Wed, 25 Mar 2015 10:59:24 +0000 (UTC) From: Andrew Rybchenko <arybchik@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r280557 - stable/10/sys/dev/sfxge Message-ID: <201503251059.t2PAxOaj000587@svn.freebsd.org>
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Author: arybchik Date: Wed Mar 25 10:59:24 2015 New Revision: 280557 URL: https://svnweb.freebsd.org/changeset/base/280557 Log: MFC: 279094 sfxge: more accurate calculation of maximum number of TSO segments Sponsored by: Solarflare Communications, Inc. Approved by: gnn (mentor) Modified: stable/10/sys/dev/sfxge/sfxge_tx.c stable/10/sys/dev/sfxge/sfxge_tx.h Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/dev/sfxge/sfxge_tx.c ============================================================================== --- stable/10/sys/dev/sfxge/sfxge_tx.c Wed Mar 25 10:58:21 2015 (r280556) +++ stable/10/sys/dev/sfxge/sfxge_tx.c Wed Mar 25 10:59:24 2015 (r280557) @@ -72,10 +72,10 @@ __FBSDID("$FreeBSD$"); * maximum mbuf length we might need more than a ring-ful of * descriptors, but this should not happen in practice except * due to deliberate attack. In that case we will truncate - * the output at a packet boundary. Allow for a reasonable - * minimum MSS of 512. + * the output at a packet boundary. */ -#define SFXGE_TSO_MAX_DESC ((65535 / 512) * 2 + SFXGE_TX_MAPPING_MAX_SEG - 1) +#define SFXGE_TSO_MAX_DESC \ + (SFXGE_TSO_MAX_SEGS * 2 + SFXGE_TX_MAPPING_MAX_SEG - 1) #define SFXGE_TXQ_BLOCK_LEVEL(_entries) ((_entries) - SFXGE_TSO_MAX_DESC) #ifdef SFXGE_HAVE_MQ Modified: stable/10/sys/dev/sfxge/sfxge_tx.h ============================================================================== --- stable/10/sys/dev/sfxge/sfxge_tx.h Wed Mar 25 10:58:21 2015 (r280556) +++ stable/10/sys/dev/sfxge/sfxge_tx.h Wed Mar 25 10:59:24 2015 (r280557) @@ -36,12 +36,22 @@ #include <netinet/ip.h> #include <netinet/tcp.h> +/* Maximum size of TSO packet */ +#define SFXGE_TSO_MAX_SIZE (65535) + +/* + * Maximum number of segments to be created for a TSO packet. + * Allow for a reasonable minimum MSS of 512. + */ +#define SFXGE_TSO_MAX_SEGS howmany(SFXGE_TSO_MAX_SIZE, 512) + /* Maximum number of DMA segments needed to map an mbuf chain. With * TSO, the mbuf length may be just over 64K, divided into 2K mbuf * clusters. (The chain could be longer than this initially, but can * be shortened with m_collapse().) */ -#define SFXGE_TX_MAPPING_MAX_SEG (64 / 2 + 1) +#define SFXGE_TX_MAPPING_MAX_SEG \ + (1 + howmany(SFXGE_TSO_MAX_SIZE, MCLBYTES)) /* * Buffer mapping flags.
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