Date: Mon, 8 Jun 2009 09:22:56 +0000 (UTC) From: Kip Macy <kmacy@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r193699 - user/kmacy/releng_7_2_fcs/sys/kern Message-ID: <200906080922.n589MuOc022144@svn.freebsd.org>
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Author: kmacy Date: Mon Jun 8 09:22:56 2009 New Revision: 193699 URL: http://svn.freebsd.org/changeset/base/193699 Log: try to avoid taking a cache miss on the newly allocated mbuf Modified: user/kmacy/releng_7_2_fcs/sys/kern/uipc_mbuf.c Modified: user/kmacy/releng_7_2_fcs/sys/kern/uipc_mbuf.c ============================================================================== --- user/kmacy/releng_7_2_fcs/sys/kern/uipc_mbuf.c Mon Jun 8 09:19:25 2009 (r193698) +++ user/kmacy/releng_7_2_fcs/sys/kern/uipc_mbuf.c Mon Jun 8 09:22:56 2009 (r193699) @@ -100,6 +100,7 @@ struct mbuf * m_getm2(struct mbuf *m, int len, int how, short type, int flags) { struct mbuf *mb, *nm = NULL, *mtail = NULL; + int size; KASSERT(len >= 0, ("%s: len is < 0", __func__)); @@ -112,25 +113,30 @@ m_getm2(struct mbuf *m, int len, int how /* Loop and append maximum sized mbufs to the chain tail. */ while (len > 0) { - if (len > MCLBYTES) + if (len > MCLBYTES) { mb = m_getjcl(how, type, (flags & M_PKTHDR), MJUMPAGESIZE); - else if (len >= MINCLSIZE) + size = MJUMPAGESIZE; + } else if (len >= MINCLSIZE) { mb = m_getcl(how, type, (flags & M_PKTHDR)); - else if (flags & M_PKTHDR) + size = MCLBYTES; + } else if (flags & M_PKTHDR) { mb = m_gethdr(how, type); - else + size = MHLEN; + } else { mb = m_get(how, type); - + size = MLEN; + } /* Fail the whole operation if one mbuf can't be allocated. */ if (mb == NULL) { if (nm != NULL) m_freem(nm); return (NULL); } - + prefetch(mb); + /* Book keeping. */ - len -= mb->m_size; + len -= size; if (mtail != NULL) mtail->m_next = mb; else
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