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| author | mohans <mohans@FreeBSD.org> | 2007-01-25 01:05:23 +0000 |
|---|---|---|
| committer | mohans <mohans@FreeBSD.org> | 2007-01-25 01:05:23 +0000 |
| commit | 83064ec323555287e3f57d6a7467f4f3017aacbf (patch) | |
| tree | 29d5e3c67fe7103c5fe9363f82111c4d5203c0f7 /sys/kern/kern_mbuf.c | |
| parent | a6abba5b5e0e902b8ffef521a7ae00fe2efdc14a (diff) | |
| download | FreeBSD-src-83064ec323555287e3f57d6a7467f4f3017aacbf.zip FreeBSD-src-83064ec323555287e3f57d6a7467f4f3017aacbf.tar.gz | |
Fix for problems that occur when all mbuf clusters migrate to the mbuf packet
zone. Cluster allocations fail when this happens. Also processes that may have
blocked on cluster allocations will never be woken up. Thanks to rwatson for
an overview of the issue and pointers to the mbuma paper and his tool to dump
out UMA zones.
Reviewed by: andre@
Diffstat (limited to 'sys/kern/kern_mbuf.c')
| -rw-r--r-- | sys/kern/kern_mbuf.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c index 0f99924..3934965 100644 --- a/sys/kern/kern_mbuf.c +++ b/sys/kern/kern_mbuf.c @@ -372,6 +372,14 @@ mb_dtor_pack(void *mem, int size, void *arg) #ifdef INVARIANTS trash_dtor(m->m_ext.ext_buf, MCLBYTES, arg); #endif + /* + * If there are processes blocked on zone_clust, waiting for pages to be freed up, + * cause them to be woken up by draining the packet zone. We are exposed to a race here + * (in the check for the UMA_ZFLAG_FULL) where we might miss the flag set, but that is + * deliberate. We don't want to acquire the zone lock for every mbuf free. + */ + if (uma_zone_exhausted_nolock(zone_clust)) + zone_drain(zone_pack); } /* |
