search for: nswbuf

...kgdb) During such an fsync, DTrace shows me that syncer sleeps of 50-200ms are happening up to 8 or 10 times a second. When this happens, a bunch of postgres threads become blocked in vn_write() waiting for the vnode lock to become free. It looks like the write-clustering code is limited to using (nswbuf / 2) pbufs, and FreeBSD prevents one from setting nswbuf to anything greater than 256. Since the sleeps are happening in the write-clustering code, I tried disabling write clustering on the mountpoint (with the noclusterw mount option) and found that this replaces my problem with another one: the...

...--- /usr/src/sys.org/sys/buf.h Sat Jan 25 20:02:23 2003 +++ sys/buf.h Sat Apr 12 00:30:48 2003 @@ -478,6 +478,7 @@ extern char *buffers; /* The buffer con extern int bufpages; /* Number of memory pages in the buffer pool. */ extern struct buf *swbuf; /* Swap I/O buffer headers. */ extern int nswbuf; /* Number of swap I/O buffer headers. */ +extern int stratcalls; /* I/O ops since last buffer sync */ extern TAILQ_HEAD(swqueue, buf) bswlist; extern TAILQ_HEAD(bqueues, buf) bufqueues[BUFFER_QUEUES]; --- /usr/src/sys.org/sys/vnode.h Sun Dec 29 19:19:53 2002 +++ sys/vnode.h Sat Apr 12 00:06...