linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Minchan Kim <minchan@kernel.org>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Kyungmin Park <kmpark@infradead.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Michal Nazarewicz <mina86@mina86.com>,
	Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
	Linux-Next <linux-next@vger.kernel.org>
Subject: Re: [PATCH] mm: cma: Discard clean pages during contiguous allocation instead of migration
Date: Thu, 13 Sep 2012 15:19:22 -0700	[thread overview]
Message-ID: <20120913151922.b8893088.akpm@linux-foundation.org> (raw)
In-Reply-To: <CAMuHMdXWZ=Jeggd7cT_LXK0MTnmFAf+cWEhC75B1gCcSd3eWeg@mail.gmail.com>

On Thu, 13 Sep 2012 21:17:19 +0200
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> On Tue, Sep 11, 2012 at 2:41 AM, Minchan Kim <minchan@kernel.org> wrote:
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -674,8 +674,10 @@ static enum page_references page_check_references(struct page *page,
> >  static unsigned long shrink_page_list(struct list_head *page_list,
> >                                       struct zone *zone,
> >                                       struct scan_control *sc,
> > +                                     enum ttu_flags ttu_flags,
> 
> "enum ttu_flags" is defined on CONFIG_MMU=y only, causing on nommu:
> 
> mm/vmscan.c:677:26: error: parameter 4 ('ttu_flags') has incomplete type
> mm/vmscan.c:987:5: error: 'TTU_UNMAP' undeclared (first use in this function)
> mm/vmscan.c:987:15: error: 'TTU_IGNORE_ACCESS' undeclared (first use
> in this function)
> mm/vmscan.c:1312:56: error: 'TTU_UNMAP' undeclared (first use in this function)
> 
> E.g.
> http://kisskb.ellerman.id.au/kisskb/buildresult/7191694/ (h8300-defconfig)
> http://kisskb.ellerman.id.au/kisskb/buildresult/7191858/ (sh-allnoconfig)

hm, OK, the means by which current mainline avoids build errors is
either clever or lucky.

			switch (try_to_unmap(page, TTU_UNMAP)) {

gets preprocessed into

			switch (2) {

so the cmopiler never gets to see the TTU_ symbol at all.  Because it
happens to be inside the try_to_unmap() call.


I guess we can just make ttu_flags visible to NOMMU:


--- a/include/linux/rmap.h~mm-cma-discard-clean-pages-during-contiguous-allocation-instead-of-migration-fix-fix
+++ a/include/linux/rmap.h
@@ -71,6 +71,17 @@ struct anon_vma_chain {
 #endif
 };
 
+enum ttu_flags {
+	TTU_UNMAP = 0,			/* unmap mode */
+	TTU_MIGRATION = 1,		/* migration mode */
+	TTU_MUNLOCK = 2,		/* munlock mode */
+	TTU_ACTION_MASK = 0xff,
+
+	TTU_IGNORE_MLOCK = (1 << 8),	/* ignore mlock */
+	TTU_IGNORE_ACCESS = (1 << 9),	/* don't age */
+	TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
+};
+
 #ifdef CONFIG_MMU
 static inline void get_anon_vma(struct anon_vma *anon_vma)
 {
@@ -164,16 +175,6 @@ int page_referenced(struct page *, int i
 int page_referenced_one(struct page *, struct vm_area_struct *,
 	unsigned long address, unsigned int *mapcount, unsigned long *vm_flags);
 
-enum ttu_flags {
-	TTU_UNMAP = 0,			/* unmap mode */
-	TTU_MIGRATION = 1,		/* migration mode */
-	TTU_MUNLOCK = 2,		/* munlock mode */
-	TTU_ACTION_MASK = 0xff,
-
-	TTU_IGNORE_MLOCK = (1 << 8),	/* ignore mlock */
-	TTU_IGNORE_ACCESS = (1 << 9),	/* don't age */
-	TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
-};
 #define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)
 
 int try_to_unmap(struct page *, enum ttu_flags flags);
_

--
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:[~2012-09-13 22:19 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-11  0:41 [PATCH] mm: cma: Discard clean pages during contiguous allocation instead of migration Minchan Kim
2012-09-11  8:59 ` Mel Gorman
2012-09-11 11:15 ` Michal Nazarewicz
2012-09-11 11:23   ` Kyungmin Park
2012-09-12 20:07 ` Andrew Morton
2012-09-12 23:58   ` Minchan Kim
2012-09-13 19:17 ` Geert Uytterhoeven
2012-09-13 22:19   ` Andrew Morton [this message]
2012-09-14  0:10     ` Minchan Kim

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=20120913151922.b8893088.akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=geert@linux-m68k.org \
    --cc=kmpark@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-next@vger.kernel.org \
    --cc=m.szyprowski@samsung.com \
    --cc=mgorman@suse.de \
    --cc=mina86@mina86.com \
    --cc=minchan@kernel.org \
    --cc=riel@redhat.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;
as well as URLs for NNTP newsgroup(s).