On Fri, May 01, 2020 at 06:27:07PM -0400, Douglas Gilbert wrote:
> On 2020-04-22 5:54 a.m., Ming Lei wrote:
> > The following three fields of scsi_host_template are referenced in
> > scsi IO submission path, so put them together into one cacheline:
> >
> > - cmd_size
> > - queuecommand
> > - commit_rqs
> >
> > Cc: Bart Van Assche <bvanassche@xxxxxxx>
> > Cc: Christoph Hellwig <hch@xxxxxx>
> > Cc: John Garry <john.garry@xxxxxxxxxx>
> > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> > ---
> > V2:
> > - move the 3 fields at the beginning of scsi_host_template
> > - comment why we do this way
> >
> > include/scsi/scsi_host.h | 72 ++++++++++++++++++++++------------------
> > 1 file changed, 39 insertions(+), 33 deletions(-)
>
> Hi,
> I would like to test this patch. However it doesn't apply on Martin's
> tree (all 3 chunks fail). Could you post a clean version?
>
> Doug Gilbert
>
Hi Doug,
Please try the following one:
>From 356220ede9f06a20d90fa387cc84eb63eea2335d Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@xxxxxxxxxx>
Date: Tue, 21 Apr 2020 17:27:30 +0800
Subject: [PATCH] scsi: put hot fields of scsi_host_template into one cacheline
The following three fields of scsi_host_template are referenced in
scsi IO submission path, so put them together into one cacheline:
- cmd_size
- queuecommand
- commit_rqs
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: John Garry <john.garry@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
include/scsi/scsi_host.h | 72 ++++++++++++++++++++++------------------
1 file changed, 39 insertions(+), 33 deletions(-)
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 46ef8cccc982..6fa2697638b4 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -30,40 +30,15 @@ struct scsi_transport_template;
#define MODE_TARGET 0x02
struct scsi_host_template {
- struct module *module;
- const char *name;
-
/*
- * The info function will return whatever useful information the
- * developer sees fit. If not provided, then the name field will
- * be used instead.
- *
- * Status: OPTIONAL
+ * Put fields referenced in IO submission path together in
+ * same cacheline
*/
- const char *(* info)(struct Scsi_Host *);
/*
- * Ioctl interface
- *
- * Status: OPTIONAL
- */
- int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
- void __user *arg);
-
-
-#ifdef CONFIG_COMPAT
- /*
- * Compat handler. Handle 32bit ABI.
- * When unknown ioctl is passed return -ENOIOCTLCMD.
- *
- * Status: OPTIONAL
+ * Additional per-command data allocated for the driver.
*/
- int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
- void __user *arg);
-#endif
-
- int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
- int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
+ unsigned int cmd_size;
/*
* The queuecommand function is used to queue up a scsi
@@ -111,6 +86,41 @@ struct scsi_host_template {
*/
void (*commit_rqs)(struct Scsi_Host *, u16);
+ struct module *module;
+ const char *name;
+
+ /*
+ * The info function will return whatever useful information the
+ * developer sees fit. If not provided, then the name field will
+ * be used instead.
+ *
+ * Status: OPTIONAL
+ */
+ const char *(*info)(struct Scsi_Host *);
+
+ /*
+ * Ioctl interface
+ *
+ * Status: OPTIONAL
+ */
+ int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
+ void __user *arg);
+
+
+#ifdef CONFIG_COMPAT
+ /*
+ * Compat handler. Handle 32bit ABI.
+ * When unknown ioctl is passed return -ENOIOCTLCMD.
+ *
+ * Status: OPTIONAL
+ */
+ int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
+ void __user *arg);
+#endif
+
+ int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
+ int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
+
/*
* This is an error handling strategy routine. You don't need to
* define one of these if you don't want to - there is a default
@@ -475,10 +485,6 @@ struct scsi_host_template {
*/
u64 vendor_id;
- /*
- * Additional per-command data allocated for the driver.
- */
- unsigned int cmd_size;
struct scsi_host_cmd_pool *cmd_pool;
/* Delay for runtime autosuspend */
--
2.25.2
--
Ming
