Create a global thread hash table to speed up thread lookup, use

rwlock to protect the table. In old code, thread lookup is done with
process lock held, to find a thread, kernel has to iterate through
process and thread list, this is quite inefficient.
With this change, test shows in extreme case performance is
dramatically improved.

Earlier patch was reviewed by: jhb, julian

1 files changed, 8 insertions, 4 deletions

diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index e05106a..69b4e0a 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -609,16 +609,20 @@ aio_init_aioinfo(struct proc *p)
 static int
 aio_sendsig(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
 {
-	int ret = 0;
+	struct thread *td;
+	int error;
 
-	PROC_LOCK(p);
+	error = sigev_findtd(p, sigev, &td);
+	if (error)
+		return (error);
 	if (!KSI_ONQ(ksi)) {
+		ksiginfo_set_sigev(ksi, sigev);
 		ksi->ksi_code = SI_ASYNCIO;
 		ksi->ksi_flags |= KSI_EXT | KSI_INS;
-		ret = psignal_event(p, sigev, ksi);
+		tdsendsignal(p, td, ksi->ksi_signo, ksi);
 	}
 	PROC_UNLOCK(p);
-	return (ret);
+	return (error);
 }
 
 /*