175b3f31d3
option. This can occur when an nfsiod thread that already holds a buffer lock attempts to acquire a vnode lock on an entry in the directory (a LOR) when another thread holding the vnode lock is waiting on an nfsiod thread. This patch avoids the deadlock by disabling readahead for this case, so the nfsiod threads never do readdirplus. Since readaheads for directories need the directory offset cookie from the previous read, they cannot normally happen in parallel. As such, testing by jhb@ and myself didn't find any performance degredation when this patch is applied. If there is a case where this results in a significant performance degradation, mounting without the "rdirplus" option can be done to re-enable readahead for directories. Reported and tested by: jhb Reviewed by: jhb MFC after: 2 weeks |
||
|---|---|---|
| .. | ||
| nfs_bio.c | ||
| nfs_kdtrace.c | ||
| nfs_krpc.c | ||
| nfs_nfsiod.c | ||
| nfs_node.c | ||
| nfs_subs.c | ||
| nfs_vfsops.c | ||
| nfs_vnops.c | ||
| nfs.h | ||
| nfsargs.h | ||
| nfsm_subs.h | ||
| nfsmount.h | ||
| nfsnode.h | ||
| nfsstats.h | ||
| nlminfo.h | ||