From: John David Anglin <dave.anglin@bell.net>
To: Matthew Wilcox <willy@linux.intel.com>
Cc: linux-mm@kvack.org, "David S. Miller" <davem@davemloft.net>,
sparclinux@vger.kernel.org, linux-parisc@vger.kernel.org,
linux-mips@linux-mips.org
Subject: Re: [PATCH] remap_file_pages needs to check for cache coherency
Date: Fri, 27 Dec 2013 14:13:16 -0500 [thread overview]
Message-ID: <BLU0-SMTP17D26551261DF285A7E6F497CD0@phx.gbl> (raw)
In-Reply-To: <20131227180018.GC4945@linux.intel.com>
On 27-Dec-13, at 1:00 PM, Matthew Wilcox wrote:
> +#ifdef __ARCH_FORCE_SHMLBA
> + /* Is the mapping cache-coherent? */
> + if ((pgoff ^ linear_page_index(vma, start)) &
> + ((SHMLBA-1) >> PAGE_SHIFT))
> + goto out;
> +#endif
I think this will cause problems on PA-RISC. The reason is we have an
additional offset
for mappings. See get_offset() in sys_parisc.c.
SHMLBA is 4 MB on PA-RISC. If we limit ourselves to aligned mappings,
we run out of
memory very quickly. Even with our current implementation, we fail
the perl locales test
with locales-all installed.
Dave
--
John David Anglin dave.anglin@bell.net
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next prev parent reply other threads:[~2013-12-27 19:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-27 18:00 Matthew Wilcox
2013-12-27 18:48 ` David Miller
2013-12-27 19:20 ` Matthew Wilcox
2013-12-27 19:13 ` John David Anglin [this message]
2013-12-27 19:33 ` Matthew Wilcox
2013-12-27 19:47 ` John David Anglin
2013-12-27 20:14 ` John David Anglin
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