linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
	Nikolay Borisov <kernel@kyup.com>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Michal Hocko <mhocko@suse.com>
Subject: [PATCH] mm: remove __GFP_NOFAIL is deprecated comment
Date: Thu, 25 Feb 2016 11:43:22 +0100	[thread overview]
Message-ID: <1456397002-27172-1-git-send-email-mhocko@kernel.org> (raw)

From: Michal Hocko <mhocko@suse.com>

647757197cd3 ("mm: clarify __GFP_NOFAIL deprecation status") was
incomplete and didn't remove the comment about __GFP_NOFAIL being
deprecated in buffered_rmqueue. Let's get rid of this leftover
but keep the WARN_ON_ONCE for order > 1 because we should really
discourage from using __GFP_NOFAIL with higher order allocations
because those are just too subtle.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
Hi,
this popped out when discussing another patch http://lkml.kernel.org/r/56CEC568.6080809@kyup.com
so I think it is worth removing the comment.

 mm/page_alloc.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1993894b4219..109d975a7172 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2347,19 +2347,11 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
 		list_del(&page->lru);
 		pcp->count--;
 	} else {
-		if (unlikely(gfp_flags & __GFP_NOFAIL)) {
-			/*
-			 * __GFP_NOFAIL is not to be used in new code.
-			 *
-			 * All __GFP_NOFAIL callers should be fixed so that they
-			 * properly detect and handle allocation failures.
-			 *
-			 * We most definitely don't want callers attempting to
-			 * allocate greater than order-1 page units with
-			 * __GFP_NOFAIL.
-			 */
-			WARN_ON_ONCE(order > 1);
-		}
+		/*
+		 * We most definitely don't want callers attempting to
+		 * allocate greater than order-1 page units with __GFP_NOFAIL.
+		 */
+		WARN_ON_ONCE(unlikely(gfp_flags & __GFP_NOFAIL) && (order > 1));
 		spin_lock_irqsave(&zone->lock, flags);
 
 		page = NULL;
-- 
2.7.0

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

             reply	other threads:[~2016-02-25 10:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-25 10:43 Michal Hocko [this message]
2016-02-25 11:36 ` Nikolay Borisov
2016-02-25 13:48   ` Michal Hocko
2016-03-07 14:57     ` Vlastimil Babka

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=1456397002-27172-1-git-send-email-mhocko@kernel.org \
    --to=mhocko@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=kernel@kyup.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=rientjes@google.com \
    /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