On Mon, 2021-03-22 at 17:02 -0400, Laurence Oberman wrote:
Hello
We have been struggling with this for years.
Systems are getting so large now that a system with multi-terabyte
memory and 1000's of device paths is becoming common.
For example, customers are seeing 16 paths and with a 1000 LUNS thats
16000 multiline console log discovery etc.
We land up in Emergency mode and various incatanations of "cant boot"
due to console putput slowdown that (while worse on serial consoles)
is
still huge overhead that can even require us to use watchdog_thresh
on
the kernel line to prevent the NMI's
I started thinking about a new parameter for scsi_mod that could be
used by sd and the scsi_dh_alua probing / discovery messaging (that
is
so noisy), to quieten it down.
Before I even put efort into this, I wanted to see if you folks have
an
appetite for this.
We have been blacklisting HBA drivers and using verious printk masks
etc to overcome this but a way to mask this within sd.c and
scsi_dh_alua.c I think could work better.
It would not be the default of course but an option to be added for
these huge customers.
I would look do do the minimal logging for a device discovery, just
so
some messaging is there for debug etc and I think it will help.
If this is a crazy idea, let me know and I wont pursue it, but I
decided to just put it out there.
Best Regards
Laurence Oberman
Replying to my own thread with more information
RFE: Introduce two new macros to manage the crazy amount of boot
logging we get with the large LUN count systems
sd_printk_boot_control
sdev_printk_boot_control
These macros have an extra parameter boot_log_enable and if its default
(1) then logs are printed
adding scsi_mod.scsi_alua_boot_logging=0 will quiet down the logging
for these huge systems
With no parameter (default) nothing changes in the logging
With boot log control and regular console
134s to boot and 1987 lines with 80 devices and 2 paths
With no boot control (default) and regular console
170s to boot and about 4000 lines of logging
The patch inline is not final so I did not send with git given this is
an RFE.
t is included to show the changes I was thinking about.
Tests
---------
One Example
With boot log control and regular console
134s to boot and 1987 lines with 80 devices and 2 paths
With no boot control (default) and regular console
170s to boot and about 4000 lines of logging
This one is even easier to explain why we need this.
I could not boot this host unless I blacklisted the lpfc and qla2xxx
drivers.
It has 128 CPUS. (DL980G7)
I am not using a serial console either, I see the same hard lockup for
the console vprintk on the VGA console.
It has 4 Adapter ports and 8 paths for some LUNS and 16 for others and
would hard lockup on both consoles even with watchdog_thresh=30
Anyway Now I am able to boot.
This issue is not uncommon lately with a lot of customers landing up in
Emergency Shells or having crazy long boot times or worse not booting
at all
Proposed code changes, if there is any interest will clean up after
comments and send.
Note that there is no way I could find to change the current macros to
allow a new argument when passed to be used such that I did not have to
change every sd_printk and every sdev_printk.
This way I aonly change the wones I wanted a small selection and I call
the new macros.
Again, just need a OK, clean maybe we can consider or simply a NAK.
A NAK is fine with a simple explanation why.
Thanks fr the consideration
Laurence
Example patch only, to still be checked and fixed and correct the
wrapping and column length later.
It was tested against 5.12 latest and against RHEL8.3 kernels
commit 52105c69ef20d57ed9f219486ac821e5d29ea5eb (HEAD -> loberman-
upstream)
Author: Laurence Oberman <loberman@xxxxxxxxxx>
Date: Wed Mar 24 14:10:49 2021 -0400
Add two new macros for managing the boot logging for large LUN
count configurations
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c
b/drivers/scsi/device_handler/scsi_dh_alua.c
index ea436a14087f..9ce5e70ecbcc 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -58,6 +58,8 @@ static LIST_HEAD(port_group_list);
static DEFINE_SPINLOCK(port_group_lock);
static struct workqueue_struct *kaluad_wq;
+extern int scsi_alua_boot_logging;
+
struct alua_port_group {
struct kref kref;
struct rcu_head rcu;
@@ -282,16 +284,18 @@ static int alua_check_tpgs(struct scsi_device
*sdev)
tpgs = scsi_device_tpgs(sdev);
switch (tpgs) {
case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
- sdev_printk(KERN_INFO, sdev,
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
"%s: supports implicit and explicit
TPGS\n",
ALUA_DH_NAME);
break;
case TPGS_MODE_EXPLICIT:
- sdev_printk(KERN_INFO, sdev, "%s: supports explicit
TPGS\n",
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
+ "%s: supports explicit TPGS\n",
ALUA_DH_NAME);
break;
case TPGS_MODE_IMPLICIT:
- sdev_printk(KERN_INFO, sdev, "%s: supports implicit
TPGS\n",
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
+ "%s: supports implicit TPGS\n",
ALUA_DH_NAME);
break;
case TPGS_MODE_NONE:
@@ -343,13 +347,14 @@ static int alua_check_vpd(struct scsi_device
*sdev, struct alua_dh_data *h,
return SCSI_DH_NOMEM;
return SCSI_DH_DEV_UNSUPP;
}
- if (pg->device_id_len)
- sdev_printk(KERN_INFO, sdev,
+ if (pg->device_id_len) {
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
"%s: device %s port group %x rel port
%x\n",
ALUA_DH_NAME, pg->device_id_str,
group_id, rel_port);
+ }
else
- sdev_printk(KERN_INFO, sdev,
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
"%s: port group %x rel port %x\n",
ALUA_DH_NAME, group_id, rel_port);
@@ -635,7 +640,7 @@ static int alua_rtpg(struct scsi_device *sdev,
struct alua_port_group *pg)
pg->transition_tmo = ALUA_FAILOVER_TIMEOUT;
if (orig_transition_tmo != pg->transition_tmo) {
- sdev_printk(KERN_INFO, sdev,
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
"%s: transition timeout set to %d
seconds\n",
ALUA_DH_NAME, pg->transition_tmo);
pg->expiry = jiffies + pg->transition_tmo * HZ;
@@ -686,7 +691,7 @@ static int alua_rtpg(struct scsi_device *sdev,
struct alua_port_group *pg)
if (transitioning_sense)
pg->state = SCSI_ACCESS_STATE_TRANSITIONING;
- sdev_printk(KERN_INFO, sdev,
+ sdev_printk_boot_control(KERN_INFO, sdev,
scsi_alua_boot_logging,
"%s: port group %02x state %c %s supports
%c%c%c%c%c%c%c\n",
ALUA_DH_NAME, pg->group_id, print_alua_state(pg-
state),
pg->pref ? "preferred" : "non-preferred",
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 24619c3bebd5..b91c46be345d 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -86,6 +86,9 @@ unsigned int scsi_logging_level;
EXPORT_SYMBOL(scsi_logging_level);
#endif
+int scsi_alua_boot_logging = 1;
+EXPORT_SYMBOL(scsi_alua_boot_logging);
+
/*
* Domain for asynchronous system resume operations. It is marked
'exclusive'
* to avoid being included in the async_synchronize_full() that is
invoked by
@@ -749,6 +752,8 @@ MODULE_LICENSE("GPL");
module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
+module_param(scsi_alua_boot_logging, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(scsi_alua_boot_logging, "If set to 0 will silence
SCSI and ALUA discovery logging on boot");
static int __init init_scsi(void)
{
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 9af50e6f94c4..282e7ad8370f 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -87,6 +87,8 @@ static const char *scsi_null_device_strs =
"nullnullnullnull";
static u64 max_scsi_luns = MAX_SCSI_LUNS;
+extern int scsi_alua_boot_logging;
+
module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_luns,
"last scsi LUN (should be between 1 and 2^64-1)");
@@ -863,7 +865,8 @@ static int scsi_add_lun(struct scsi_device *sdev,
unsigned char *inq_result,
if (inq_result[7] & 0x10)
sdev->sdtr = 1;
- sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
+ sdev_printk_boot_control(KERN_NOTICE, sdev,
scsi_alua_boot_logging,
+ "%s %.8s %.16s %.4s PQ: %d "
"ANSI: %d%s\n", scsi_device_type(sdev->type),
sdev->vendor, sdev->model, sdev->rev,
sdev->inq_periph_qual, inq_result[2] & 0x07,
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index ed0b1bb99f08..c64451a6d1fd 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -104,6 +104,8 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_ZBC);
#define SD_MINORS 0
#endif
+extern int scsi_alua_boot_logging;
+
static void sd_config_discard(struct scsi_disk *, unsigned int);
static void sd_config_write_same(struct scsi_disk *);
static int sd_revalidate_disk(struct gendisk *);
@@ -2205,7 +2207,8 @@ sd_spinup_disk(struct scsi_disk *sdkp)
* Issue command to spin up drive when not
ready
*/
if (!spintime) {
- sd_printk(KERN_NOTICE, sdkp, "Spinning
up disk...");
+ sd_printk_boot_control(KERN_NOTICE,
sdkp, scsi_alua_boot_logging,
+ "Spinning up disk...");
cmd[0] = START_STOP;
cmd[1] = 1; /* Return immediately
*/
memset((void *) &cmd[2], 0, 8);
@@ -2407,7 +2410,7 @@ static int read_capacity_16(struct scsi_disk
*sdkp, struct scsi_device *sdp,
alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) *
sector_size;
blk_queue_alignment_offset(sdp->request_queue, alignment);
if (alignment && sdkp->first_scan)
- sd_printk(KERN_NOTICE, sdkp,
+ sd_printk_boot_control(KERN_NOTICE, sdkp,
scsi_alua_boot_logging,
"physical block alignment offset: %u\n",
alignment);
if (buffer[14] & 0x80) { /* LBPME */
@@ -2524,11 +2527,11 @@ sd_read_capacity(struct scsi_disk *sdkp,
unsigned char *buffer)
if ((sizeof(sdkp->capacity) > 4) &&
(sdkp->capacity > 0xffffffffULL)) {
int old_sector_size = sector_size;
- sd_printk(KERN_NOTICE, sdkp, "Very big device.
"
+ sd_printk_boot_control(KERN_NOTICE, sdkp,
scsi_alua_boot_logging, "Very big device. "
"Trying to use READ
CAPACITY(16).\n");
sector_size = read_capacity_16(sdkp, sdp,
buffer);
if (sector_size < 0) {
- sd_printk(KERN_NOTICE, sdkp,
+ sd_printk_boot_control(KERN_NOTICE,
sdkp, scsi_alua_boot_logging,
"Using 0xffffffff as device
size\n");
sdkp->capacity = 1 + (sector_t)
0xffffffff;
sector_size = old_sector_size;
@@ -2613,13 +2616,13 @@ sd_print_capacity(struct scsi_disk *sdkp,
string_get_size(sdkp->capacity, sector_size,
STRING_UNITS_10, cap_str_10,
sizeof(cap_str_10));
- sd_printk(KERN_NOTICE, sdkp,
+ sd_printk_boot_control(KERN_NOTICE,
sdkp,scsi_alua_boot_logging,
"%llu %d-byte logical blocks: (%s/%s)\n",
(unsigned long long)sdkp->capacity,
sector_size, cap_str_10, cap_str_2);
if (sdkp->physical_block_size != sector_size)
- sd_printk(KERN_NOTICE, sdkp,
+ sd_printk_boot_control(KERN_NOTICE, sdkp,
scsi_alua_boot_logging,
"%u-byte physical blocks\n",
sdkp->physical_block_size);
}
@@ -2687,9 +2690,10 @@ sd_read_write_protect_flag(struct scsi_disk
*sdkp, unsigned char *buffer)
sdkp->write_prot = ((data.device_specific & 0x80) !=
0);
set_disk_ro(sdkp->disk, sdkp->write_prot);
if (sdkp->first_scan || old_wp != sdkp->write_prot) {
- sd_printk(KERN_NOTICE, sdkp, "Write Protect is
%s\n",
+ sd_printk_boot_control(KERN_NOTICE, sdkp,
scsi_alua_boot_logging,
+ "Write Protect is %s\n",
sdkp->write_prot ? "on" : "off");
- sd_printk(KERN_DEBUG, sdkp, "Mode Sense:
%4ph\n", buffer);
+ sd_printk_boot_control(KERN_DEBUG, sdkp,
scsi_alua_boot_logging, "Mode Sense: %4ph\n", buffer);
}
}
}
@@ -2837,7 +2841,7 @@ sd_read_cache_type(struct scsi_disk *sdkp,
unsigned char *buffer)
if (sdkp->first_scan || old_wce != sdkp->WCE ||
old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
- sd_printk(KERN_NOTICE, sdkp,
+ sd_printk_boot_control(KERN_NOTICE, sdkp,
scsi_alua_boot_logging,
"Write cache: %s, read cache: %s,
%s\n",
sdkp->WCE ? "enabled" : "disabled",
sdkp->RCD ? "disabled" : "enabled",
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index b59136c4125b..7e88ff08c063 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -137,7 +137,15 @@ static inline struct scsi_disk *scsi_disk(struct
gendisk *disk)
(sdsk)->disk
? \
sdev_prefix_printk(prefix, (sdsk)-
device, \
(sdsk)->disk->disk_name, fmt, ##a)
: \
- sdev_printk(prefix, (sdsk)->device, fmt, ##a)
+ sdev_printk(prefix, (sdsk)->device, fmt, ##a)
+
+#define sd_printk_boot_control(prefix, sdsk, boot_log_enable, fmt,
a...) \
+ if (boot_log_enable)
{ \
+ (sdsk)->disk
? \
+ sdev_prefix_printk(prefix, (sdsk)-
device, \
+ (sdsk)->disk->disk_name, fmt, ##a)
: \
+ sdev_printk(prefix, (sdsk)->device, fmt,
##a); \
+ }
#define sd_first_printk(prefix, sdsk, fmt,
a...) \
do
{ \
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 4383d93110f8..5802b17c21f3 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -62,6 +62,8 @@ static int sg_version_num = 30536; /* 2 digits for
each component */
static char *sg_version_date = "20140603";
static int sg_proc_init(void);
+
+extern int scsi_alua_boot_logging;
