Commit 00778e22 authored by Steve French's avatar Steve French
Browse files

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: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarAurelien Aptel <aaptel@suse.com>
parent 1c3a13a3

fs/cifs/cifsfs.c

+13 −0
Original line number Diff line number Diff line
@@ -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);

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

fs/cifs/transport.c

+12 −3
Original line number Diff line number Diff line
@@ -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) &&

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