[PATCH] bounce: call flush_dcache_page after bounce_copy_vec
From: Bryan Wu <hidden>
Date: 2010-09-09 00:50:05
Also in:
linux-mm, lkml
On Wed, Sep 8, 2010 at 4:45 AM, Gary King [off-list ref] wrote:
I have been seeing problems on Tegra 2 (ARMv7 SMP) systems with HIGHMEM enabled on 2.6.35 (plus some patches targetted at 2.6.36 to perform cache maintenance lazily), and the root cause appears to be that the mm bouncing code is calling flush_dcache_page before it copies the bounce buffer into the bio. The patch below reorders these two operations, and eliminates numerous arbitrary application crashes on my dev system.
We also experience the package building failure on OMAP4 SMP system with HIGHMEM enabled on 2.6.35. Thanks a lot for this fixing, we will try it later soon. -Bryan
quoted hunk ↗ jump to hunk
Gary -- From 678c9bca8d8a8f254f28af91e69fad3aa1be7593 Mon Sep 17 00:00:00 2001 From: Gary King <redacted> Date: Mon, 6 Sep 2010 15:37:12 -0700 Subject: bounce: call flush_dcache_page after bounce_copy_vec the bounced page needs to be flushed after data is copied into it, to ensure that architecture implementations can synchronize instruction and data caches if necessary. Signed-off-by: Gary King <redacted> --- ?mm/bounce.c | ? ?2 +- ?1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/mm/bounce.c b/mm/bounce.c index 13b6dad..1481de6 100644 --- a/mm/bounce.c +++ b/mm/bounce.c@@ -116,8 +116,8 @@ static void copy_to_high_bio_irq(struct bio *to, struct bio *from)? ? ? ? ? ? ? ? */ ? ? ? ? ? ? ? ?vfrom = page_address(fromvec->bv_page) + tovec->bv_offset; - ? ? ? ? ? ? ? flush_dcache_page(tovec->bv_page); ? ? ? ? ? ? ? ?bounce_copy_vec(tovec, vfrom); + ? ? ? ? ? ? ? flush_dcache_page(tovec->bv_page); ? ? ? ?} ?} -- 1.7.0.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel