Module Name: src
Committed By: ad
Date: Tue Apr 21 21:46:07 UTC 2020
Modified Files:
src/sys/sys: filedesc.h
Log Message:
- Give cwdi_lock its own cache line, for multithreaded processes.
- Comments.
To generate a diff of this commit:
cvs rdiff -u -r1.67 -r1.68 src/sys/sys/filedesc.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/sys/filedesc.h
diff -u src/sys/sys/filedesc.h:1.67 src/sys/sys/filedesc.h:1.68
--- src/sys/sys/filedesc.h:1.67 Tue Apr 21 21:42:47 2020
+++ src/sys/sys/filedesc.h Tue Apr 21 21:46:07 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: filedesc.h,v 1.67 2020/04/21 21:42:47 ad Exp $ */
+/* $NetBSD: filedesc.h,v 1.68 2020/04/21 21:46:07 ad Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -164,13 +164,21 @@ typedef struct filedesc {
uint32_t fd_dlomap[NDENTRIES];
} filedesc_t;
+/*
+ * Working directory, root and umask information. Serialization:
+ *
+ * a atomic operations
+ * l cwdi_lock
+ */
typedef struct cwdinfo {
- struct vnode *cwdi_cdir; /* current directory */
- struct vnode *cwdi_rdir; /* root directory */
- struct vnode *cwdi_edir; /* emulation root (if known) */
- krwlock_t cwdi_lock; /* lock on entire struct */
- u_int cwdi_cmask; /* mask for file creation */
- u_int cwdi_refcnt; /* reference count */
+ struct vnode *cwdi_cdir; /* l: current directory */
+ struct vnode *cwdi_rdir; /* l: root directory */
+ struct vnode *cwdi_edir; /* l: emulation root (if known) */
+ u_int cwdi_cmask; /* a: mask for file creation */
+ u_int cwdi_refcnt; /* a: reference count */
+
+ krwlock_t cwdi_lock /* :: lock on struct */
+ __aligned(COHERENCY_UNIT); /* -> gets own cache line */
} cwdinfo_t;
#ifdef _KERNEL
