[PATCH] add mallinfo() information to pool-usage report

[Jeremy Allison]

On Thu, Apr 04, 2019 at 11:00:34AM +0200, Ralph Wuerthner via samba-technical wrote:
> Hi!
> 
> Please see attached patch set to enhance the pool-usage report from
> smbcontrol with information available from mallinfo(). In addition to the
> talloc report we found the mallinfo() data quite handy to investigate a
> potential memory leak in Samba. To my knowledge mallinfo() is available on
> Linux, BSD, and AIX.
> The CI pipeline is running at
> https://gitlab.com/samba-team/devel/samba/pipelines/55161485

LGTM. RB+.

Can I get a second Team reviewer ?

Jeremy.


> From d221912134f4750bdee23d1dfbe2531e03c31d6d Mon Sep 17 00:00:00 2001
> From: Ralph Wuerthner <ralph.wuerthner at de.ibm.com>
> Date: Fri, 29 Mar 2019 12:30:45 +0100
> Subject: [PATCH 1/2] s3-messages: modify msg_pool_usage() to allow enhanced
>  memory reports
> 
> Signed-off-by: Ralph Wuerthner <ralph.wuerthner at de.ibm.com>
> ---
>  source3/lib/tallocmsg.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/source3/lib/tallocmsg.c b/source3/lib/tallocmsg.c
> index 18b16ed..b5ab21c 100644
> --- a/source3/lib/tallocmsg.c
> +++ b/source3/lib/tallocmsg.c
> @@ -30,21 +30,32 @@ static void msg_pool_usage(struct messaging_context *msg_ctx,
>  			   struct server_id src,
>  			   DATA_BLOB *data)
>  {
> -	char *report;
> +	char *report = NULL;
> +	int iov_size = 0;
> +	struct iovec iov[1];
>  
>  	SMB_ASSERT(msg_type == MSG_REQ_POOL_USAGE);
>  
>  	DEBUG(2,("Got POOL_USAGE\n"));
>  
>  	report = talloc_report_str(msg_ctx, NULL);
> -
>  	if (report != NULL) {
> -		messaging_send_buf(msg_ctx, src, MSG_POOL_USAGE,
> -				   (uint8_t *)report,
> -				   talloc_get_size(report)-1);
> +		iov[iov_size].iov_base = report;
> +		iov[iov_size].iov_len = talloc_get_size(report) - 1;
> +		iov_size++;
> +	}
> +
> +	if (iov_size) {
> +		messaging_send_iov(msg_ctx,
> +				   src,
> +				   MSG_POOL_USAGE,
> +				   iov,
> +				   iov_size,
> +				   NULL,
> +				   0);
>  	}
>  
> -	talloc_free(report);
> +	TALLOC_FREE(report);
>  }
>  
>  /**
> -- 
> 2.7.4
> 
> 
> From 7a192974651567ec16b60a5c0fd22ac83da6c2d8 Mon Sep 17 00:00:00 2001
> From: Ralph Wuerthner <ralph.wuerthner at de.ibm.com>
> Date: Fri, 29 Mar 2019 12:44:50 +0100
> Subject: [PATCH 2/2] s3-messages: add mallinfo() information to pool-usage
>  report
> 
> Signed-off-by: Ralph Wuerthner <ralph.wuerthner at de.ibm.com>
> ---
>  source3/lib/tallocmsg.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  source3/wscript         | 12 ++++++++++++
>  2 files changed, 61 insertions(+), 1 deletion(-)
> 
> diff --git a/source3/lib/tallocmsg.c b/source3/lib/tallocmsg.c
> index b5ab21c..9be1bf5 100644
> --- a/source3/lib/tallocmsg.c
> +++ b/source3/lib/tallocmsg.c
> @@ -19,7 +19,46 @@
>  #include "includes.h"
>  #include "messages.h"
>  #include "lib/util/talloc_report.h"
> +#ifdef HAVE_MALLINFO
> +#include <malloc.h>
> +#endif /* HAVE_MALLINFO */
>  
> + /**
> + * Prepare memory allocation report based on mallinfo()
> + **/
> +static char *get_mallinfo_report(void *mem_ctx)
> +{
> +	char *report = NULL;
> +#ifdef HAVE_MALLINFO
> +	struct mallinfo mi;
> +
> +	mi = mallinfo();
> +	report = talloc_asprintf(mem_ctx,
> +				 "mallinfo:\n"
> +				 "    arena: %d\n"
> +				 "    ordblks: %d\n"
> +				 "    smblks: %d\n"
> +				 "    hblks: %d\n"
> +				 "    hblkhd: %d\n"
> +				 "    usmblks: %d\n"
> +				 "    fsmblks: %d\n"
> +				 "    uordblks: %d\n"
> +				 "    fordblks: %d\n"
> +				 "    keepcost: %d\n",
> +				 mi.arena,
> +				 mi.ordblks,
> +				 mi.smblks,
> +				 mi.hblks,
> +				 mi.hblkhd,
> +				 mi.usmblks,
> +				 mi.fsmblks,
> +				 mi.uordblks,
> +				 mi.fordblks,
> +				 mi.keepcost);
> +#endif /* HAVE_MALLINFO */
> +
> +	return report;
> +}
>  /**
>   * Respond to a POOL_USAGE message by sending back string form of memory
>   * usage stats.
> @@ -31,8 +70,9 @@ static void msg_pool_usage(struct messaging_context *msg_ctx,
>  			   DATA_BLOB *data)
>  {
>  	char *report = NULL;
> +	char *mreport = NULL;
>  	int iov_size = 0;
> -	struct iovec iov[1];
> +	struct iovec iov[2];
>  
>  	SMB_ASSERT(msg_type == MSG_REQ_POOL_USAGE);
>  
> @@ -45,6 +85,13 @@ static void msg_pool_usage(struct messaging_context *msg_ctx,
>  		iov_size++;
>  	}
>  
> +	mreport = get_mallinfo_report(msg_ctx);
> +	if (mreport != NULL) {
> +		iov[iov_size].iov_base = mreport;
> +		iov[iov_size].iov_len = talloc_get_size(mreport) - 1;
> +		iov_size++;
> +	}
> +
>  	if (iov_size) {
>  		messaging_send_iov(msg_ctx,
>  				   src,
> @@ -56,6 +103,7 @@ static void msg_pool_usage(struct messaging_context *msg_ctx,
>  	}
>  
>  	TALLOC_FREE(report);
> +	TALLOC_FREE(mreport);
>  }
>  
>  /**
> diff --git a/source3/wscript b/source3/wscript
> index c93b605..97b51bb 100644
> --- a/source3/wscript
> +++ b/source3/wscript
> @@ -1517,6 +1517,18 @@ main() {
>                      define='HAVE_UNSHARE_CLONE_FS',
>                      msg='for Linux unshare(CLONE_FS)')
>  
> +    # Check for mallinfo
> +    conf.CHECK_CODE('''
> +    struct mallinfo mi;
> +    int tmp;
> +
> +    mi = mallinfo();
> +    tmp = mi.arena + mi.ordblks + mi.smblks + mi.hblks +
> +          mi.hblkhd + mi.usmblks + mi.fsmblks +  mi.uordblks +
> +          mi.fordblks + mi.keepcost;
> +    return tmp;
> +    ''', 'HAVE_MALLINFO', msg="Checking for mallinfo()", headers='malloc.h')
> +
>      #
>      # cluster support (CTDB)
>      #
> -- 
> 2.7.4
>