Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-rdma@vger.kernel.org,
	Arnd Bergmann <arnd@arndb.de>, Jason Gunthorpe <jgg@mellanox.com>,
	Bernard Metzler <bmt@zurich.ibm.com>,
	"Matthew Wilcox (Oracle)" <willy@infradead.org>,
	Michal Hocko <mhocko@suse.com>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] mm: add dummy can_do_mlock() helper
Date: Mon,  9 Sep 2019 22:41:40 +0200
Message-ID: <20190909204201.931830-1-arnd@arndb.de> (raw)

On kernels without CONFIG_MMU, we get a link error for the siw
driver:

drivers/infiniband/sw/siw/siw_mem.o: In function `siw_umem_get':
siw_mem.c:(.text+0x4c8): undefined reference to `can_do_mlock'

This is probably not the only driver that needs the function
and could otherwise build correctly without CONFIG_MMU, so
add a dummy variant that always returns false.

Fixes: 2251334dcac9 ("rdma/siw: application buffer management")
Suggested-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/mm.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 66f296181bcc..cc292273e6ba 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1424,7 +1424,11 @@ extern void pagefault_out_of_memory(void);
 
 extern void show_free_areas(unsigned int flags, nodemask_t *nodemask);
 
+#ifdef CONFIG_MMU
 extern bool can_do_mlock(void);
+#else
+static inline bool can_do_mlock(void) { return false; }
+#endif
 extern int user_shm_lock(size_t, struct user_struct *);
 extern void user_shm_unlock(size_t, struct user_struct *);
 
-- 
2.20.0



             reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-09 20:41 Arnd Bergmann [this message]
2019-09-10  7:10 ` Michal Hocko
2019-09-10  7:31   ` Arnd Bergmann
2019-09-10  8:40   ` Jason Gunthorpe

Reply instructions:

You may reply publically 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=20190909204201.931830-1-arnd@arndb.de \
    --to=arnd@arndb.de \
    --cc=akpm@linux-foundation.org \
    --cc=bmt@zurich.ibm.com \
    --cc=jgg@mellanox.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=mhocko@suse.com \
    --cc=willy@infradead.org \
    /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

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org linux-mm@archiver.kernel.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox