diff options
Diffstat (limited to 'sys/kern/vfs_bio.c')
| -rw-r--r-- | sys/kern/vfs_bio.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 14ae4a8..a0d693c 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -1235,9 +1235,8 @@ brelse(struct buf * bp) bufcountwakeup(); /* - * Something we can maybe free. + * Something we can maybe free or reuse */ - if (bp->b_bufsize || bp->b_kvasize) bufspacewakeup(); @@ -1304,7 +1303,7 @@ bqrelse(struct buf * bp) } /* - * Something we can maybe wakeup + * Something we can maybe free or reuse. */ if (bp->b_bufsize && !(bp->b_flags & B_DELWRI)) bufspacewakeup(); @@ -1551,10 +1550,13 @@ restart: } /* - * Nada. If we are allowed to allocate an EMPTY - * buffer, go get one. + * If we could not find or were not allowed to reuse a + * CLEAN buffer, check to see if it is ok to use an EMPTY + * buffer. We can only use an EMPTY buffer if allocating + * its KVA would not otherwise run us out of buffer space. */ - if (nbp == NULL && defrag == 0 && bufspace < hibufspace) { + if (nbp == NULL && defrag == 0 && + bufspace + maxsize < hibufspace) { nqindex = QUEUE_EMPTY; nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTY]); } @@ -1686,6 +1688,11 @@ restart: goto restart; } + /* + * If we are overcomitted then recover the buffer and its + * KVM space. This occurs in rare situations when multiple + * processes are blocked in getnewbuf() or allocbuf(). + */ if (bufspace >= hibufspace) flushingbufs = 1; if (flushingbufs && bp->b_kvasize != 0) { |
