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Message-ID: <20080610163141.GD12985@sgi.com>
Date: Tue, 10 Jun 2008 11:31:41 -0500
From: Dean Nelson <dcn@....com>
To: akpm@...ux-foundation.org
Cc: linux-kernel@...r.kernel.org
Subject: [Patch 3/3] sgi-xp: add 'jiffies' to reserved page's timestamp name
Rename XPC's reserved page's timestamp member to reflect the units of time
involved.
Signed-off-by: Dean Nelson <dcn@....com>
---
On Sun, Jun 08, 2008 at 05:15:37PM -0700, Andrew Morton wrote:
> On Fri, 6 Jun 2008 11:52:16 -0500 Dean Nelson <dcn@....com> wrote:
>
> > + unsigned long stamp; /* time when reserved page was setup by XPC */
>
> "time" is a rubbery concept in-kernel. What are the units of this?
> microseconds? jiffies? seconds?
>
> At the least, the covering comment should make clear what units this
> variable is using. Better would be to actually embed the units in the
> variable's identifier. Because it's awfulyl easy to make mistakes over
> this, and not knowing the units makes the code harder to follow.
Agreed. Thanks for the feedback.
Dean
drivers/misc/sgi-xp/xpc.h | 6 +++---
drivers/misc/sgi-xp/xpc_main.c | 8 ++++----
drivers/misc/sgi-xp/xpc_partition.c | 14 +++++++-------
drivers/misc/sgi-xp/xpc_sn2.c | 26 ++++++++++++++------------
4 files changed, 28 insertions(+), 26 deletions(-)
Index: linux-next/drivers/misc/sgi-xp/xpc.h
===================================================================
--- linux-next.orig/drivers/misc/sgi-xp/xpc.h 2008-06-10 10:17:06.091909005 -0500
+++ linux-next/drivers/misc/sgi-xp/xpc.h 2008-06-10 10:17:12.688730757 -0500
@@ -87,7 +87,7 @@
* which are partition specific (vars part). These are setup by XPC.
* (Local partition's vars pointers are xpc_vars and xpc_vars_part.)
*
- * Note: Until 'stamp' is set non-zero, the partition XPC code has not been
+ * Note: Until 'ts_jiffies' is set non-zero, the partition XPC code has not been
* initialized.
*/
struct xpc_rsvd_page {
@@ -101,7 +101,7 @@ struct xpc_rsvd_page {
u64 vars_pa; /* physical address of struct xpc_vars */
u64 activate_mq_gpa; /* global phys address of activate_mq */
} sn;
- unsigned long stamp; /* time when reserved page was setup by XPC */
+ unsigned long ts_jiffies; /* timestamp when rsvd pg was setup by XPC */
u64 pad2[10]; /* align to last u64 in 2nd 64-byte cacheline */
u64 SAL_nasids_size; /* SAL: size of each nasid mask in bytes */
};
@@ -534,7 +534,7 @@ struct xpc_partition {
/* XPC HB infrastructure */
u8 remote_rp_version; /* version# of partition's rsvd pg */
- unsigned long remote_rp_stamp; /* time when rsvd pg was initialized */
+ unsigned long remote_rp_ts_jiffies; /* timestamp when rsvd pg setup */
u64 remote_rp_pa; /* phys addr of partition's rsvd pg */
u64 last_heartbeat; /* HB at last read */
u32 activate_IRQ_rcvd; /* IRQs since activation */
Index: linux-next/drivers/misc/sgi-xp/xpc_main.c
===================================================================
--- linux-next.orig/drivers/misc/sgi-xp/xpc_main.c 2008-06-10 10:16:48.593729274 -0500
+++ linux-next/drivers/misc/sgi-xp/xpc_main.c 2008-06-10 10:17:12.812746205 -0500
@@ -862,8 +862,8 @@ xpc_do_exit(enum xp_retval reason)
DBUG_ON(xpc_any_partition_engaged());
DBUG_ON(xpc_any_hbs_allowed() != 0);
- /* indicate to others that our reserved page is uninitialized */
- xpc_rsvd_page->stamp = 0;
+ /* a zero timestamp indicates our rsvd page is not initialized */
+ xpc_rsvd_page->ts_jiffies = 0;
if (reason == xpUnloading) {
(void)unregister_die_notifier(&xpc_die_notifier);
@@ -1152,8 +1152,8 @@ xpc_init(void)
/* initialization was not successful */
out_3:
- /* indicate to others that our reserved page is uninitialized */
- xpc_rsvd_page->stamp = 0;
+ /* a zero timestamp indicates our rsvd page is not initialized */
+ xpc_rsvd_page->ts_jiffies = 0;
(void)unregister_die_notifier(&xpc_die_notifier);
(void)unregister_reboot_notifier(&xpc_reboot_notifier);
Index: linux-next/drivers/misc/sgi-xp/xpc_partition.c
===================================================================
--- linux-next.orig/drivers/misc/sgi-xp/xpc_partition.c 2008-06-10 10:17:06.071906513 -0500
+++ linux-next/drivers/misc/sgi-xp/xpc_partition.c 2008-06-10 10:17:12.976766637 -0500
@@ -133,7 +133,7 @@ xpc_setup_rsvd_page(void)
{
struct xpc_rsvd_page *rp;
u64 rp_pa;
- unsigned long new_stamp;
+ unsigned long new_ts_jiffies;
/* get the local reserved page's address */
@@ -183,10 +183,10 @@ xpc_setup_rsvd_page(void)
* This signifies to the remote partition that our reserved
* page is initialized.
*/
- new_stamp = jiffies;
- if (new_stamp == 0 || new_stamp == rp->stamp)
- new_stamp++;
- rp->stamp = new_stamp;
+ new_ts_jiffies = jiffies;
+ if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
+ new_ts_jiffies++;
+ rp->ts_jiffies = new_ts_jiffies;
return rp;
}
@@ -225,8 +225,8 @@ xpc_get_remote_rp(int nasid, unsigned lo
discovered_nasids[l] |= remote_part_nasids[l];
}
- /* see if the reserved page has been set up by XPC */
- if (remote_rp->stamp == 0)
+ /* zero timestamp indicates the reserved page has not been setup */
+ if (remote_rp->ts_jiffies == 0)
return xpRsvdPageNotSet;
if (XPC_VERSION_MAJOR(remote_rp->version) !=
Index: linux-next/drivers/misc/sgi-xp/xpc_sn2.c
===================================================================
--- linux-next.orig/drivers/misc/sgi-xp/xpc_sn2.c 2008-06-10 10:17:06.095909503 -0500
+++ linux-next/drivers/misc/sgi-xp/xpc_sn2.c 2008-06-10 10:17:13.000769626 -0500
@@ -863,8 +863,8 @@ xpc_partition_deactivation_requested_sn2
*/
static void
xpc_update_partition_info_sn2(struct xpc_partition *part, u8 remote_rp_version,
- unsigned long *remote_rp_stamp, u64 remote_rp_pa,
- u64 remote_vars_pa,
+ unsigned long *remote_rp_ts_jiffies,
+ u64 remote_rp_pa, u64 remote_vars_pa,
struct xpc_vars_sn2 *remote_vars)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
@@ -873,9 +873,9 @@ xpc_update_partition_info_sn2(struct xpc
dev_dbg(xpc_part, " remote_rp_version = 0x%016x\n",
part->remote_rp_version);
- part->remote_rp_stamp = *remote_rp_stamp;
- dev_dbg(xpc_part, " remote_rp_stamp = 0x%016lx\n",
- part->remote_rp_stamp);
+ part->remote_rp_ts_jiffies = *remote_rp_ts_jiffies;
+ dev_dbg(xpc_part, " remote_rp_ts_jiffies = 0x%016lx\n",
+ part->remote_rp_ts_jiffies);
part->remote_rp_pa = remote_rp_pa;
dev_dbg(xpc_part, " remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
@@ -933,7 +933,7 @@ xpc_identify_activate_IRQ_req_sn2(int na
u64 remote_vars_pa;
int remote_rp_version;
int reactivate = 0;
- unsigned long remote_rp_stamp = 0;
+ unsigned long remote_rp_ts_jiffies = 0;
short partid;
struct xpc_partition *part;
struct xpc_partition_sn2 *part_sn2;
@@ -952,7 +952,7 @@ xpc_identify_activate_IRQ_req_sn2(int na
remote_vars_pa = remote_rp->sn.vars_pa;
remote_rp_version = remote_rp->version;
- remote_rp_stamp = remote_rp->stamp;
+ remote_rp_ts_jiffies = remote_rp->ts_jiffies;
partid = remote_rp->SAL_partid;
part = &xpc_partitions[partid];
@@ -981,8 +981,9 @@ xpc_identify_activate_IRQ_req_sn2(int na
part->act_state == XPC_P_INACTIVE) {
xpc_update_partition_info_sn2(part, remote_rp_version,
- &remote_rp_stamp, remote_rp_pa,
- remote_vars_pa, remote_vars);
+ &remote_rp_ts_jiffies,
+ remote_rp_pa, remote_vars_pa,
+ remote_vars);
if (xpc_partition_deactivation_requested_sn2(partid)) {
/*
@@ -999,7 +1000,7 @@ xpc_identify_activate_IRQ_req_sn2(int na
DBUG_ON(part->remote_rp_version == 0);
DBUG_ON(part_sn2->remote_vars_version == 0);
- if (remote_rp_stamp != part->remote_rp_stamp) {
+ if (remote_rp_ts_jiffies != part->remote_rp_ts_jiffies) {
/* the other side rebooted */
@@ -1007,8 +1008,9 @@ xpc_identify_activate_IRQ_req_sn2(int na
DBUG_ON(xpc_partition_deactivation_requested_sn2(partid));
xpc_update_partition_info_sn2(part, remote_rp_version,
- &remote_rp_stamp, remote_rp_pa,
- remote_vars_pa, remote_vars);
+ &remote_rp_ts_jiffies,
+ remote_rp_pa, remote_vars_pa,
+ remote_vars);
reactivate = 1;
}
--
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