Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress

From: kernel test robot <lkp@intel.com>
To: Mel Gorman <mgorman@suse.de>, Andrew Morton <akpm@linux-foundation.org>
Cc: kbuild-all@lists.01.org,
	Linux Memory Management List <linux-mm@kvack.org>,
	Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
	Alexey Avramov <hakavlad@inbox.lv>,
	Rik van Riel <riel@surriel.com>, Mike Galbraith <efault@gmx.de>,
	Darrick Wong <djwong@kernel.org>,
	regressions@lists.linux.dev,
	Linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress
Date: Thu, 2 Dec 2021 22:51:35 +0800	[thread overview]
Message-ID: <202112022232.gARZWe0c-lkp@intel.com> (raw)
In-Reply-To: <20211202131842.9217-1-mgorman@techsingularity.net>

Hi Mel,

I love your patch! Perhaps something to improve:

[auto build test WARNING on hnaz-mm/master]

url:    https://github.com/0day-ci/linux/commits/Mel-Gorman/mm-vmscan-Reduce-throttling-due-to-a-failure-to-make-progress/20211202-212004
base:   https://github.com/hnaz/linux-mm master
config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20211202/202112022232.gARZWe0c-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/01dada07590ae9c69a9415ba9af96d5ae184d861
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Mel-Gorman/mm-vmscan-Reduce-throttling-due-to-a-failure-to-make-progress/20211202-212004
        git checkout 01dada07590ae9c69a9415ba9af96d5ae184d861
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> mm/vmscan.c:1024:6: warning: no previous prototype for 'skip_throttle_noprogress' [-Wmissing-prototypes]
    1024 | bool skip_throttle_noprogress(pg_data_t *pgdat)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~

vim +/skip_throttle_noprogress +1024 mm/vmscan.c

  1023	
> 1024	bool skip_throttle_noprogress(pg_data_t *pgdat)
  1025	{
  1026		int reclaimable = 0, write_pending = 0;
  1027		int i;
  1028	
  1029		/*
  1030		 * If kswapd is disabled, reschedule if necessary but do not
  1031		 * throttle as the system is likely near OOM.
  1032		 */
  1033		if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES)
  1034			return true;
  1035	
  1036		/*
  1037		 * If there are a lot of dirty/writeback pages then do not
  1038		 * throttle as throttling will occur when the pages cycle
  1039		 * towards the end of the LRU if still under writeback.
  1040		 */
  1041		for (i = 0; i < MAX_NR_ZONES; i++) {
  1042			struct zone *zone = pgdat->node_zones + i;
  1043	
  1044			if (!populated_zone(zone))
  1045				continue;
  1046	
  1047			reclaimable += zone_reclaimable_pages(zone);
  1048			write_pending += zone_page_state_snapshot(zone,
  1049							  NR_ZONE_WRITE_PENDING);
  1050		}
  1051		if (2 * write_pending <= reclaimable)
  1052			return true;
  1053	
  1054		return false;
  1055	}
  1056	

---
0-DAY CI Kernel Test Service, Intel Corporation
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