Updated to address problem Aurelien noted (forgot to multiply
slow_rsp_threshold by HZ)
On Tue, Sep 18, 2018 at 4:10 AM Steve French <smfrench@xxxxxxxxx> wrote:
>
> (Thanks to Metze for suggestion)
>
> /proc/fs/cifs/Stats when CONFIG_CIFS_STATS2 is enabled logs 'slow'
> responses, but depending on the server you are debugging a
> one second timeout may be too fast, so allow setting it to
> a larger number of seconds via new module parameter
>
> /sys/module/cifs/parameters/slow_rsp_threshold
>
> or via modprobe:
>
> slow_rsp_threshold:Amount of time (in seconds) to wait before
> logging that a response is delayed.
> Default: 1 (if set to 0 disables msg). (uint)
>
> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
> ---
> fs/cifs/cifsfs.c | 13 +++++++++++++
> fs/cifs/cifsglob.h | 1 +
> fs/cifs/transport.c | 7 ++++---
> 3 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 7065426b3280..45ea2429ab15 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -81,6 +81,14 @@ module_param(cifs_max_pending, uint, 0444);
> MODULE_PARM_DESC(cifs_max_pending, "Simultaneous requests to server for "
> "CIFS/SMB1 dialect (N/A for SMB3) "
> "Default: 32767 Range: 2 to 32767.");
> +#ifdef CONFIG_CIFS_STATS2
> +unsigned int slow_rsp_threshold = 1;
> +module_param(slow_rsp_threshold, uint, 0644);
> +MODULE_PARM_DESC(slow_rsp_threshold, "Amount of time (in seconds) to wait "
> + "before logging that a response is delayed. "
> + "Default: 1 (if set to 0 disables msg).");
> +#endif /* STATS2 */
> +
> module_param(enable_oplocks, bool, 0644);
> MODULE_PARM_DESC(enable_oplocks, "Enable or disable oplocks. Default: y/Y/1");
>
> @@ -1418,6 +1426,11 @@ init_cifs(void)
> #ifdef CONFIG_CIFS_STATS2
> atomic_set(&totBufAllocCount, 0);
> atomic_set(&totSmBufAllocCount, 0);
> + if (slow_rsp_threshold < 1)
> + cifs_dbg(FYI, "slow_response_threshold msgs disabled\n");
> + else if (slow_rsp_threshold > 32767)
> + cifs_dbg(VFS,
> + "slow response threshold set higher than recommended\n");
> #endif /* CONFIG_CIFS_STATS2 */
>
> atomic_set(&midCount, 0);
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 9dcaed031843..d59588e4aeb4 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -1715,6 +1715,7 @@ GLOBAL_EXTERN atomic_t bufAllocCount; /*
> current number allocated */
> #ifdef CONFIG_CIFS_STATS2
> GLOBAL_EXTERN atomic_t totBufAllocCount; /* total allocated over all time */
> GLOBAL_EXTERN atomic_t totSmBufAllocCount;
> +extern unsigned int slow_rsp_threshold; /* number of secs before logging */
> #endif
> GLOBAL_EXTERN atomic_t smBufAllocCount;
> GLOBAL_EXTERN atomic_t midCount;
> diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> index b48f43963da6..fe49733766d6 100644
> --- a/fs/cifs/transport.c
> +++ b/fs/cifs/transport.c
> @@ -113,9 +113,10 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
> cifs_small_buf_release(midEntry->resp_buf);
> #ifdef CONFIG_CIFS_STATS2
> now = jiffies;
> - /* commands taking longer than one second are indications that
> - something is wrong, unless it is quite a slow link or server */
> - if (time_after(now, midEntry->when_alloc + HZ) &&
> + /* commands taking longer than one second (default) can be indications
> + that something is wrong, unless it is quite a slow link or server */
> + if ((slow_rsp_threshold != 0) &&
> + time_after(now, midEntry->when_alloc + slow_rsp_threshold) &&
> (midEntry->command != command)) {
> /* smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command */
> if ((le16_to_cpu(midEntry->command) < NUMBER_OF_SMB2_COMMANDS) &&
> --
>
> --
> Thanks,
>
> Steve
--
Thanks,
Steve
From 9ea12867def2b640eaba03e00738ef1e1ceebed9 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Tue, 18 Sep 2018 14:05:18 -0500
Subject: [PATCH] smb3: add way to control slow response threshold for logging
and stats
/proc/fs/cifs/Stats when CONFIG_CIFS_STATS2 is enabled logs 'slow'
responses, but depending on the server you are debugging a
one second timeout may be too fast, so allow setting it to
a larger number of seconds via new module parameter
/sys/module/cifs/parameters/slow_rsp_threshold
or via modprobe:
slow_rsp_threshold:Amount of time (in seconds) to wait before
logging that a response is delayed.
Default: 1 (if set to 0 disables msg). (uint)
Recommended values are 0 (disabled) to 32767 (9 hours) with
the default remaining as 1 second.
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
---
fs/cifs/cifsfs.c | 13 +++++++++++++
fs/cifs/cifsglob.h | 1 +
fs/cifs/transport.c | 15 ++++++++++++---
3 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index af6c2e1795ef..ba0054604f85 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -81,6 +81,14 @@ module_param(cifs_max_pending, uint, 0444);
MODULE_PARM_DESC(cifs_max_pending, "Simultaneous requests to server for "
"CIFS/SMB1 dialect (N/A for SMB3) "
"Default: 32767 Range: 2 to 32767.");
+#ifdef CONFIG_CIFS_STATS2
+unsigned int slow_rsp_threshold = 1;
+module_param(slow_rsp_threshold, uint, 0644);
+MODULE_PARM_DESC(slow_rsp_threshold, "Amount of time (in seconds) to wait "
+ "before logging that a response is delayed. "
+ "Default: 1 (if set to 0 disables msg).");
+#endif /* STATS2 */
+
module_param(enable_oplocks, bool, 0644);
MODULE_PARM_DESC(enable_oplocks, "Enable or disable oplocks. Default: y/Y/1");
@@ -1418,6 +1426,11 @@ init_cifs(void)
#ifdef CONFIG_CIFS_STATS2
atomic_set(&totBufAllocCount, 0);
atomic_set(&totSmBufAllocCount, 0);
+ if (slow_rsp_threshold < 1)
+ cifs_dbg(FYI, "slow_response_threshold msgs disabled\n");
+ else if (slow_rsp_threshold > 32767)
+ cifs_dbg(VFS,
+ "slow response threshold set higher than recommended (0 to 32767)\n");
#endif /* CONFIG_CIFS_STATS2 */
atomic_set(&midCount, 0);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 9dcaed031843..d59588e4aeb4 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1715,6 +1715,7 @@ GLOBAL_EXTERN atomic_t bufAllocCount; /* current number allocated */
#ifdef CONFIG_CIFS_STATS2
GLOBAL_EXTERN atomic_t totBufAllocCount; /* total allocated over all time */
GLOBAL_EXTERN atomic_t totSmBufAllocCount;
+extern unsigned int slow_rsp_threshold; /* number of secs before logging */
#endif
GLOBAL_EXTERN atomic_t smBufAllocCount;
GLOBAL_EXTERN atomic_t midCount;
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index b48f43963da6..781d0b4fe7a2 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -113,9 +113,18 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
cifs_small_buf_release(midEntry->resp_buf);
#ifdef CONFIG_CIFS_STATS2
now = jiffies;
- /* commands taking longer than one second are indications that
- something is wrong, unless it is quite a slow link or server */
- if (time_after(now, midEntry->when_alloc + HZ) &&
+ /*
+ * commands taking longer than one second (default) can be indications
+ * that something is wrong, unless it is quite a slow link or a very
+ * busy server. Note that this calc is unlikely or impossible to wrap
+ * as long as slow_rsp_threshold is not set way above recommended max
+ * value (32767 ie 9 hours) and is generally harmless even if wrong
+ * since only affects debug counters - so leaving the calc as simple
+ * comparison rather than doing multiple conversions and overflow
+ * checks
+ */
+ if ((slow_rsp_threshold != 0) &&
+ time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
(midEntry->command != command)) {
/* smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command */
if ((le16_to_cpu(midEntry->command) < NUMBER_OF_SMB2_COMMANDS) &&
--
2.17.1
