From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 38BE28D0047 for ; Thu, 10 Mar 2011 02:37:55 -0500 (EST) Date: Thu, 10 Mar 2011 02:37:51 -0500 From: Christoph Hellwig Subject: Re: [PATCH] xfs: flush vmap aliases when mapping fails Message-ID: <20110310073751.GB25374@infradead.org> References: <1299713876-7747-1-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1299713876-7747-1-git-send-email-david@fromorbit.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner Cc: xfs@oss.sgi.com, npiggin@kernel.dk, linux-mm@kvack.org On Thu, Mar 10, 2011 at 10:37:56AM +1100, Dave Chinner wrote: > From: Dave Chinner > > On 32 bit systems, vmalloc space is limited and XFS can chew through > it quickly as the vmalloc space is lazily freed. This can result in > failure to map buffers, even when there is apparently large amounts > of vmalloc space available. Hence, if we fail to map a buffer, purge > the aliases that have not yet been freed to hopefuly free up enough > vmalloc space to allow a retry to succeed. IMHO this should be done by vm_map_ram internally. If we can't get the core code fixes we can put this in as a last resort. > > Signed-off-by: Dave Chinner > --- > fs/xfs/linux-2.6/xfs_buf.c | 14 +++++++++++--- > 1 files changed, 11 insertions(+), 3 deletions(-) > > diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c > index 3cc671c..a5a260f 100644 > --- a/fs/xfs/linux-2.6/xfs_buf.c > +++ b/fs/xfs/linux-2.6/xfs_buf.c > @@ -455,9 +455,17 @@ _xfs_buf_map_pages( > bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; > bp->b_flags |= XBF_MAPPED; > } else if (flags & XBF_MAPPED) { > - bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, > - -1, PAGE_KERNEL); > - if (unlikely(bp->b_addr == NULL)) > + int retried = 0; > + > + do { > + bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, > + -1, PAGE_KERNEL); > + if (bp->b_addr) > + break; > + vm_unmap_aliases(); > + } while (retried++ <= 1); > + > + if (!bp->b_addr) > return -ENOMEM; > bp->b_addr += bp->b_offset; > bp->b_flags |= XBF_MAPPED; > -- > 1.7.2.3 > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs ---end quoted text--- -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org