From 736e4b67ae336f0e5dd884ac73f0471b5d758676 Mon Sep 17 00:00:00 2001 From: Mike Smith Date: Tue, 28 Dec 1999 06:35:57 +0000 Subject: [PATCH] Actively limit the allocation of mbufs to NMBUFS/nmbufs and mbuf clusters to NMBCLUSTERS/nmbclusters/kern.ipc.nmbclusters. Add a read-only sysctl kern.ipc.nmbufs matching kern.ipc.nmbclusters. Submitted by: Bosko Milekic --- sys/kern/uipc_mbuf.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c index 8c3c4bfb1dc2..cc38c40e62fe 100644 --- a/sys/kern/uipc_mbuf.c +++ b/sys/kern/uipc_mbuf.c @@ -81,12 +81,14 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_wait, CTLFLAG_RW, &mbuf_wait, 0, ""); SYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RW, &mbstat, mbstat, ""); SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RD, - &nmbclusters, 0, "Maximum number of mbuf clusters avaliable"); + &nmbclusters, 0, "Maximum number of mbuf clusters available"); +SYSCTL_INT(_kern_ipc, OID_AUTO, nmbufs, CTLFLAG_RD, &nmbufs, 0, + "Maximum number of mbufs available"); #ifndef NMBCLUSTERS #define NMBCLUSTERS (512 + MAXUSERS * 16) #endif TUNABLE_INT_DECL("kern.ipc.nmbclusters", NMBCLUSTERS, nmbclusters); -TUNABLE_INT_DECL("kern.ipc.nmbufs", NMBCLUSTERS * 4, nmbufs); /* XXX fixup? */ +TUNABLE_INT_DECL("kern.ipc.nmbufs", NMBCLUSTERS * 4, nmbufs); static void m_reclaim __P((void)); @@ -140,6 +142,14 @@ m_mballoc(nmb, how) register int i; int nbytes; + /* + * If we've hit the mbuf limit, stop allocating from mb_map, + * (or trying to) in order to avoid dipping into the section of + * mb_map which we've "reserved" for clusters. + */ + if ((nmb + mbstat.m_mbufs) > nmbufs) + return (0); + /* * Once we run out of map space, it will be impossible to get * any more (nothing is ever freed back to the map) @@ -266,6 +276,16 @@ m_clalloc(ncl, how) register int i; int npg; + /* + * If we've hit the mcluster number limit, stop allocating from + * mb_map, (or trying to) in order to avoid dipping into the section + * of mb_map which we've "reserved" for mbufs. + */ + if ((ncl + mbstat.m_clusters) > nmbclusters) { + mbstat.m_drops++; + return (0); + } + /* * Once we run out of map space, it will be impossible * to get any more (nothing is ever freed back to the