linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: mgorman@techsingularity.net
Cc: linux-mm@kvack.org
Subject: [bug report] mm, compaction: round-robin the order while searching the free lists for a target
Date: Wed, 9 Jan 2019 11:27:33 +0300	[thread overview]
Message-ID: <20190109082733.GA5424@kadam> (raw)

Hello Mel Gorman,

The patch 1688e2896de4: "mm, compaction: round-robin the order while
searching the free lists for a target" from Jan 8, 2019, leads to the
following static checker warning:

	mm/compaction.c:1252 next_search_order()
	warn: impossible condition '(cc->search_order < 0) => (0-u16max < 0)'

mm/compaction.c
    1243 static int next_search_order(struct compact_control *cc, int order)
    1244 {
    1245 	order--;
    1246 	if (order < 0)
    1247 		order = cc->order - 1;
    1248 
    1249 	/* Search wrapped around? */
    1250 	if (order == cc->search_order) {
    1251 		cc->search_order--;
--> 1252 		if (cc->search_order < 0)
                            ^^^^^^^^^^^^^^^^^^^^
u16 can't be negative.

    1253 			cc->search_order = cc->order - 1;
    1254 		return -1;
    1255 	}
    1256 
    1257 	return order;
    1258 }

regards,
dan carpenter

             reply	other threads:[~2019-01-09  8:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-09  8:27 Dan Carpenter [this message]
2019-01-09 10:25 ` Mel Gorman
2019-01-09 10:28   ` Dan Carpenter
2019-01-09 10:35   ` Mel Gorman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190109082733.GA5424@kadam \
    --to=dan.carpenter@oracle.com \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox