linux-kernel - Re: [PATCH V4 13/15] blk-throttle: add a mechanism to estimate IO latency

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <201611150706.Bti9nwgN%fengguang.wu@intel.com>
Date:   Tue, 15 Nov 2016 07:40:38 +0800
From:   kbuild test robot <lkp@...el.com>
To:     Shaohua Li <shli@...com>
Cc:     kbuild-all@...org, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org, Kernel-team@...com, axboe@...com,
        tj@...nel.org, vgoyal@...hat.com
Subject: Re: [PATCH V4 13/15] blk-throttle: add a mechanism to estimate IO
 latency

Hi Shaohua,

[auto build test WARNING on linus/master]
[also build test WARNING on v4.9-rc5]
[cannot apply to block/for-next next-20161114]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Shaohua-Li/blk-throttle-add-high-limit/20161115-063105
config: xtensa-allmodconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 4.9.0
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=xtensa 

All warnings (new ones prefixed by >>):

   In file included from ./arch/xtensa/include/generated/asm/div64.h:1:0,
                    from include/linux/kernel.h:142,
                    from include/linux/list.h:8,
                    from include/linux/module.h:9,
                    from block/blk-throttle.c:7:
   block/blk-throttle.c: In function 'throtl_calculate_line_slope':
   include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
     (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
                               ^
>> block/blk-throttle.c:2017:2: note: in expansion of macro 'do_div'
     do_div(xMean, valid_lat);
     ^
   include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
     (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
                               ^
   block/blk-throttle.c:2019:2: note: in expansion of macro 'do_div'
     do_div(yMean, valid_lat);
     ^
   include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
     (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
                               ^
   block/blk-throttle.c:2023:2: note: in expansion of macro 'do_div'
     do_div(slope, denominator);
     ^

vim +/do_div +2017 block/blk-throttle.c

  2001		for (i = 0; i < LATENCY_BUCKET_SIZE; i++) {
  2002			u64 x, y;
  2003	
  2004			if (td->avg_buckets[i].latency == 0)
  2005				continue;
  2006	
  2007			x = td->avg_buckets[i].size >> 10;
  2008			y = td->avg_buckets[i].latency;
  2009			sumX += x;
  2010			sumY += y;
  2011	
  2012			sumXY += x * y;
  2013			sumX2 += x * x;
  2014		}
  2015	
  2016		xMean = sumX;
> 2017		do_div(xMean, valid_lat);
  2018		yMean = sumY;
  2019		do_div(yMean, valid_lat);
  2020		denominator = sumX2 - sumX * xMean;
  2021	
  2022		slope = sumXY - sumX * yMean;
  2023		do_div(slope, denominator);
  2024		td->line_slope = slope;
  2025	}

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Download attachment ".config.gz" of type "application/gzip" (47027 bytes)