svn commit: r327409 - in stable/11/sys: conf kern security/audit sys
Mateusz Guzik
mjg at FreeBSD.org
Sun Dec 31 03:35:37 UTC 2017
Author: mjg
Date: Sun Dec 31 03:35:34 2017
New Revision: 327409
URL: https://svnweb.freebsd.org/changeset/base/327409
Log:
MFC r323235,r323236,r324789,r324863:
Introduce __read_frequently
While __read_mostly groups variables together, their placement is not
specified. In particular 2 frequently used variables can end up in
different lines.
This annotation is only expected to be used for variables read all the time,
e.g. on each syscall entry.
=============
Sprinkle __read_frequently on few obvious places.
Note that some of annotated variables should probably change their types
to something smaller, preferably bit-sized.
=============
Mark kdb_active as __read_frequently and switch to bool to eat less space.
=============
Change kdb_active type to u_char.
Fixes warnings from gcc and keeps the small size. Perhaps nesting should be moved
to another variablle.
Modified:
stable/11/sys/conf/ldscript.amd64
stable/11/sys/kern/kern_dtrace.c
stable/11/sys/kern/kern_lockstat.c
stable/11/sys/kern/kern_mutex.c
stable/11/sys/kern/kern_rwlock.c
stable/11/sys/kern/kern_sx.c
stable/11/sys/kern/subr_kdb.c
stable/11/sys/security/audit/audit.c
stable/11/sys/sys/kdb.h
stable/11/sys/sys/systm.h
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/conf/ldscript.amd64
==============================================================================
--- stable/11/sys/conf/ldscript.amd64 Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/conf/ldscript.amd64 Sun Dec 31 03:35:34 2017 (r327409)
@@ -146,6 +146,10 @@ SECTIONS
. = DATA_SEGMENT_RELRO_END (24, .);
.got.plt : { *(.got.plt) }
. = ALIGN(64);
+ .data.read_frequently :
+ {
+ *(.data.read_frequently)
+ }
.data.read_mostly :
{
*(.data.read_mostly)
Modified: stable/11/sys/kern/kern_dtrace.c
==============================================================================
--- stable/11/sys/kern/kern_dtrace.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/kern/kern_dtrace.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -54,7 +54,7 @@ dtrace_doubletrap_func_t dtrace_doubletrap_func;
dtrace_pid_probe_ptr_t dtrace_pid_probe_ptr;
dtrace_return_probe_ptr_t dtrace_return_probe_ptr;
-systrace_probe_func_t systrace_probe_func;
+systrace_probe_func_t __read_frequently systrace_probe_func;
/* Return the DTrace process data size compiled in the kernel hooks. */
size_t
Modified: stable/11/sys/kern/kern_lockstat.c
==============================================================================
--- stable/11/sys/kern/kern_lockstat.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/kern/kern_lockstat.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -62,7 +62,7 @@ SDT_PROBE_DEFINE1(lockstat, , , sx__downgrade, "struct
SDT_PROBE_DEFINE2(lockstat, , , thread__spin, "struct mtx *", "uint64_t");
-volatile int __read_mostly lockstat_enabled;
+volatile int __read_frequently lockstat_enabled;
uint64_t
lockstat_nsecs(struct lock_object *lo)
Modified: stable/11/sys/kern/kern_mutex.c
==============================================================================
--- stable/11/sys/kern/kern_mutex.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/kern/kern_mutex.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -140,7 +140,7 @@ struct lock_class lock_class_mtx_spin = {
#ifdef ADAPTIVE_MUTEXES
static SYSCTL_NODE(_debug, OID_AUTO, mtx, CTLFLAG_RD, NULL, "mtx debugging");
-static struct lock_delay_config __read_mostly mtx_delay;
+static struct lock_delay_config __read_frequently mtx_delay;
SYSCTL_INT(_debug_mtx, OID_AUTO, delay_base, CTLFLAG_RW, &mtx_delay.base,
0, "");
@@ -153,7 +153,7 @@ LOCK_DELAY_SYSINIT_DEFAULT(mtx_delay);
static SYSCTL_NODE(_debug, OID_AUTO, mtx_spin, CTLFLAG_RD, NULL,
"mtx spin debugging");
-static struct lock_delay_config __read_mostly mtx_spin_delay;
+static struct lock_delay_config __read_frequently mtx_spin_delay;
SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_base, CTLFLAG_RW,
&mtx_spin_delay.base, 0, "");
Modified: stable/11/sys/kern/kern_rwlock.c
==============================================================================
--- stable/11/sys/kern/kern_rwlock.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/kern/kern_rwlock.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -93,14 +93,14 @@ struct lock_class lock_class_rw = {
};
#ifdef ADAPTIVE_RWLOCKS
-static int rowner_retries = 10;
-static int rowner_loops = 10000;
+static int __read_frequently rowner_retries = 10;
+static int __read_frequently rowner_loops = 10000;
static SYSCTL_NODE(_debug, OID_AUTO, rwlock, CTLFLAG_RD, NULL,
"rwlock debugging");
SYSCTL_INT(_debug_rwlock, OID_AUTO, retry, CTLFLAG_RW, &rowner_retries, 0, "");
SYSCTL_INT(_debug_rwlock, OID_AUTO, loops, CTLFLAG_RW, &rowner_loops, 0, "");
-static struct lock_delay_config __read_mostly rw_delay;
+static struct lock_delay_config __read_frequently rw_delay;
SYSCTL_INT(_debug_rwlock, OID_AUTO, delay_base, CTLFLAG_RW, &rw_delay.base,
0, "");
Modified: stable/11/sys/kern/kern_sx.c
==============================================================================
--- stable/11/sys/kern/kern_sx.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/kern/kern_sx.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -142,13 +142,13 @@ struct lock_class lock_class_sx = {
#endif
#ifdef ADAPTIVE_SX
-static u_int asx_retries = 10;
-static u_int asx_loops = 10000;
+static __read_frequently u_int asx_retries = 10;
+static __read_frequently u_int asx_loops = 10000;
static SYSCTL_NODE(_debug, OID_AUTO, sx, CTLFLAG_RD, NULL, "sxlock debugging");
SYSCTL_UINT(_debug_sx, OID_AUTO, retries, CTLFLAG_RW, &asx_retries, 0, "");
SYSCTL_UINT(_debug_sx, OID_AUTO, loops, CTLFLAG_RW, &asx_loops, 0, "");
-static struct lock_delay_config __read_mostly sx_delay;
+static struct lock_delay_config __read_frequently sx_delay;
SYSCTL_INT(_debug_sx, OID_AUTO, delay_base, CTLFLAG_RW, &sx_delay.base,
0, "");
Modified: stable/11/sys/kern/subr_kdb.c
==============================================================================
--- stable/11/sys/kern/subr_kdb.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/kern/subr_kdb.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -50,7 +50,7 @@ __FBSDID("$FreeBSD$");
#include <machine/smp.h>
#endif
-int kdb_active = 0;
+u_char __read_frequently kdb_active = 0;
static void *kdb_jmpbufp = NULL;
struct kdb_dbbe *kdb_dbbe = NULL;
static struct pcb kdb_pcb;
Modified: stable/11/sys/security/audit/audit.c
==============================================================================
--- stable/11/sys/security/audit/audit.c Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/security/audit/audit.c Sun Dec 31 03:35:34 2017 (r327409)
@@ -91,7 +91,7 @@ static SYSCTL_NODE(_security, OID_AUTO, audit, CTLFLAG
*
* Define the audit control flags.
*/
-int audit_enabled;
+int __read_frequently audit_enabled;
int audit_suspended;
/*
Modified: stable/11/sys/sys/kdb.h
==============================================================================
--- stable/11/sys/sys/kdb.h Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/sys/kdb.h Sun Dec 31 03:35:34 2017 (r327409)
@@ -59,7 +59,7 @@ struct kdb_dbbe {
}; \
DATA_SET(kdb_dbbe_set, name##_dbbe)
-extern int kdb_active; /* Non-zero while in debugger. */
+extern u_char kdb_active; /* Non-zero while in debugger. */
extern int debugger_on_panic; /* enter the debugger on panic. */
extern struct kdb_dbbe *kdb_dbbe; /* Default debugger backend or NULL. */
extern struct trapframe *kdb_frame; /* Frame to kdb_trap(). */
Modified: stable/11/sys/sys/systm.h
==============================================================================
--- stable/11/sys/sys/systm.h Sun Dec 31 03:34:00 2017 (r327408)
+++ stable/11/sys/sys/systm.h Sun Dec 31 03:35:34 2017 (r327409)
@@ -138,6 +138,7 @@ void kassert_panic(const char *fmt, ...) __printflike
* Align variables.
*/
#define __read_mostly __section(".data.read_mostly")
+#define __read_frequently __section(".data.read_frequently")
#define __exclusive_cache_line __aligned(CACHE_LINE_SIZE) \
__section(".data.exclusive_cache_line")
/*
More information about the svn-src-all
mailing list