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| author | bmilekic <bmilekic@FreeBSD.org> | 2001-03-24 23:47:52 +0000 |
|---|---|---|
| committer | bmilekic <bmilekic@FreeBSD.org> | 2001-03-24 23:47:52 +0000 |
| commit | ab0c3d9c1a6d8d4b0ff2011b208ca24b5e45e83d (patch) | |
| tree | 1e8309d56e2a292ab526ff5e1f2bd5ca6e862bed /sys | |
| parent | 11442775804b9679c2c761846072b171d2507840 (diff) | |
| download | FreeBSD-src-ab0c3d9c1a6d8d4b0ff2011b208ca24b5e45e83d.zip FreeBSD-src-ab0c3d9c1a6d8d4b0ff2011b208ca24b5e45e83d.tar.gz | |
Move the atomic() mbstat.m_drops incrementing to the MGET(HDR) and
MCLGET macros in order to avoid incrementing the drop count twice.
Otherwise, in some cases, we may increment m_drops once in m_mballoc()
for example, and increment it again in m_mballoc_wait() if the
wait fails.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/uipc_mbuf.c | 24 | ||||
| -rw-r--r-- | sys/sys/mbuf.h | 11 |
2 files changed, 13 insertions, 22 deletions
diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c index b5569cd..5a23f67 100644 --- a/sys/kern/uipc_mbuf.c +++ b/sys/kern/uipc_mbuf.c @@ -245,16 +245,8 @@ m_mballoc(int nmb, int how) * Also, once we run out of map space, it will be impossible to * get any more (nothing is ever freed back to the map). */ - if (mb_map_full || ((nmb + mbstat.m_mbufs) > nmbufs)) { - /* - * Needs to be atomic as we may be incrementing it - * while holding another mutex, like mclfree. In other - * words, m_drops is not reserved solely for mbufs, - * but is also available for clusters. - */ - atomic_add_long(&mbstat.m_drops, 1); + if (mb_map_full || ((nmb + mbstat.m_mbufs) > nmbufs)) return (0); - } mtx_unlock(&mmbfree.m_mtx); p = (caddr_t)kmem_malloc(mb_map, nbytes, M_NOWAIT); @@ -343,8 +335,7 @@ m_mballoc_wait(void) atomic_add_long(&mbstat.m_wait, 1); if (mmbfree.m_head != NULL) MBWAKEUP(m_mballoc_wid); - } else - atomic_add_long(&mbstat.m_drops, 1); + } return (p); } @@ -370,10 +361,8 @@ m_clalloc(int ncl, int how) * If we've hit the mcluster number limit, stop allocating from * mb_map. */ - if (mb_map_full || ((ncl + mbstat.m_clusters) > nmbclusters)) { - atomic_add_long(&mbstat.m_drops, 1); + if (mb_map_full || ((ncl + mbstat.m_clusters) > nmbclusters)) return (0); - } mtx_unlock(&mclfree.m_mtx); p = (caddr_t)kmem_malloc(mb_map, npg_sz, @@ -384,10 +373,8 @@ m_clalloc(int ncl, int how) * Either the map is now full, or `how' is M_DONTWAIT and there * are no pages left. */ - if (p == NULL) { - atomic_add_long(&mbstat.m_drops, 1); + if (p == NULL) return (0); - } /* * We don't let go of the mutex in order to avoid a race. @@ -429,8 +416,7 @@ m_clalloc_wait(void) atomic_add_long(&mbstat.m_wait, 1); if (mclfree.m_head != NULL) MBWAKEUP(m_clalloc_wid); - } else - atomic_add_long(&mbstat.m_drops, 1); + } return (p); } diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h index 8fbf7b4..2471f7c 100644 --- a/sys/sys/mbuf.h +++ b/sys/sys/mbuf.h @@ -377,8 +377,10 @@ struct mcntfree_lst { mbtypes[_mtype]++; \ mtx_unlock(&mmbfree.m_mtx); \ _MGET_SETUP(_mm, _mtype); \ - } else \ + } else { \ mtx_unlock(&mmbfree.m_mtx); \ + atomic_add_long(&mbstat.m_drops, 1); \ + } \ (m) = _mm; \ } while (0) @@ -404,8 +406,10 @@ struct mcntfree_lst { mbtypes[_mtype]++; \ mtx_unlock(&mmbfree.m_mtx); \ _MGETHDR_SETUP(_mm, _mtype); \ - } else \ + } else { \ mtx_unlock(&mmbfree.m_mtx); \ + atomic_add_long(&mbstat.m_drops, 1); \ + } \ (m) = _mm; \ } while (0) @@ -453,7 +457,8 @@ struct mcntfree_lst { _mm->m_ext.ext_size = MCLBYTES; \ _mm->m_ext.ext_type = EXT_CLUSTER; \ } \ - } \ + } else \ + atomic_add_long(&mbstat.m_drops, 1); \ } while (0) #define MEXTADD(m, buf, size, free, args, flags, type) do { \ |
