linux-kernel - [tip:x86/mm] x86, kdump: Change copy_oldmem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 9 Sep 2010 11:57:57 GMT
From:	tip-bot for Cliff Wickman <cpw@....com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	cpw@....com, tglx@...utronix.de, mingo@...e.hu,
	ebiederm@...ssion.com
Subject: [tip:x86/mm] x86, kdump: Change copy_oldmem_page() to use cached addressing

Commit-ID:  37a2f9f30a360fb03522d15c85c78265ccd80287
Gitweb:     http://git.kernel.org/tip/37a2f9f30a360fb03522d15c85c78265ccd80287
Author:     Cliff Wickman <cpw@....com>
AuthorDate: Wed, 8 Sep 2010 10:14:27 -0500
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Thu, 9 Sep 2010 09:46:23 +0200

x86, kdump: Change copy_oldmem_page() to use cached addressing

The copy of /proc/vmcore to a user buffer proceeds much faster
if the kernel addresses memory as cached.

With this patch we have seen an increase in transfer rate from
less than 15MB/s to 80-460MB/s, depending on size of the
transfer. This makes a big difference in time needed to save a
system dump.

Signed-off-by: Cliff Wickman <cpw@....com>
Acked-by: "Eric W. Biederman" <ebiederm@...ssion.com>
Cc: kexec@...ts.infradead.org
Cc: <stable@...nel.org> # as far back as it would apply
LKML-Reference: <E1OtMLz-0001yp-Ia@...09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@...e.hu>
---
 arch/x86/kernel/crash_dump_64.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index 045b36c..bf43188 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -34,7 +34,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!csize)
 		return 0;
 
-	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
+	vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
 	if (!vaddr)
 		return -ENOMEM;
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/