diff options
| -rw-r--r-- | sys/sys/mbuf.h | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h index a936dcb9068c5..f6cf06ea83d70 100644 --- a/sys/sys/mbuf.h +++ b/sys/sys/mbuf.h @@ -244,7 +244,7 @@ union mcluster { */ union mext_refcnt { union mext_refcnt *next_ref; - u_long refcnt; + u_int refcnt; }; /* @@ -293,10 +293,10 @@ struct mcntfree_lst { #define MEXT_REM_REF(m) do { \ KASSERT((m)->m_ext.ref_cnt->refcnt > 0, ("m_ext refcnt < 0")); \ - atomic_subtract_long(&((m)->m_ext.ref_cnt->refcnt), 1); \ + atomic_subtract_int(&((m)->m_ext.ref_cnt->refcnt), 1); \ } while(0) -#define MEXT_ADD_REF(m) atomic_add_long(&((m)->m_ext.ref_cnt->refcnt), 1) +#define MEXT_ADD_REF(m) atomic_add_int(&((m)->m_ext.ref_cnt->refcnt), 1) #define _MEXT_ALLOC_CNT(m_cnt, how) do { \ union mext_refcnt *__mcnt; \ @@ -483,17 +483,22 @@ struct mcntfree_lst { mtx_exit(&mclfree.m_mtx, MTX_DEF); \ } while (0) +/* MEXTFREE: + * If the atomic_cmpset_int() returns 0, then we effectively do nothing + * in terms of "cleaning up" (freeing the ext buf and ref. counter) as + * this means that either there are still references, or another thread + * is taking care of the clean-up. + */ #define MEXTFREE(m) do { \ struct mbuf *_mmm = (m); \ \ - if (MEXT_IS_REF(_mmm)) \ - MEXT_REM_REF(_mmm); \ - else if (_mmm->m_ext.ext_type != EXT_CLUSTER) { \ - (*(_mmm->m_ext.ext_free))(_mmm->m_ext.ext_buf, \ - _mmm->m_ext.ext_args); \ - _MEXT_DEALLOC_CNT(_mmm->m_ext.ref_cnt); \ - } else { \ - _MCLFREE(_mmm->m_ext.ext_buf); \ + MEXT_REM_REF(_mmm); \ + if (atomic_cmpset_int(&_mmm->m_ext.ref_cnt->refcnt, 0, 1)) { \ + if (_mmm->m_ext.ext_type != EXT_CLUSTER) { \ + (*(_mmm->m_ext.ext_free))(_mmm->m_ext.ext_buf, \ + _mmm->m_ext.ext_args); \ + } else \ + _MCLFREE(_mmm->m_ext.ext_buf); \ _MEXT_DEALLOC_CNT(_mmm->m_ext.ref_cnt); \ } \ _mmm->m_flags &= ~M_EXT; \ |