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Konrad Rzeszutek Wilk 8eaffa67b4 xen/pat: Disable PAT support for now. ... [Pls also look at https://lkml.org/lkml/2012/2/10/228] Using of PAT to change pages from WB to WC works quite nicely. Changing it back to WB - not so much. The crux of the matter is that the code that does this (__page_change_att_set_clr) has only limited information so when it tries to the change it gets the "raw" unfiltered information instead of the properly filtered one - and the "raw" one tell it that PSE bit is on (while infact it is not). As a result when the PTE is set to be WB from WC, we get tons of: :WARNING: at arch/x86/xen/mmu.c:475 xen_make_pte+0x67/0xa0() :Hardware name: HP xw4400 Workstation .. snip.. :Pid: 27, comm: kswapd0 Tainted: G W 3.2.2-1.fc16.x86_64 #1 :Call Trace: : [<ffffffff8106dd1f>] warn_slowpath_common+0x7f/0xc0 : [<ffffffff8106dd7a>] warn_slowpath_null+0x1a/0x20 : [<ffffffff81005a17>] xen_make_pte+0x67/0xa0 : [<ffffffff810051bd>] __raw_callee_save_xen_make_pte+0x11/0x1e : [<ffffffff81040e15>] ? __change_page_attr_set_clr+0x9d5/0xc00 : [<ffffffff8114c2e8>] ? __purge_vmap_area_lazy+0x158/0x1d0 : [<ffffffff8114cca5>] ? vm_unmap_aliases+0x175/0x190 : [<ffffffff81041168>] change_page_attr_set_clr+0x128/0x4c0 : [<ffffffff81041542>] set_pages_array_wb+0x42/0xa0 : [<ffffffff8100a9b2>] ? check_events+0x12/0x20 : [<ffffffffa0074d4c>] ttm_pages_put+0x1c/0x70 [ttm] : [<ffffffffa0074e98>] ttm_page_pool_free+0xf8/0x180 [ttm] : [<ffffffffa0074f78>] ttm_pool_mm_shrink+0x58/0x90 [ttm] : [<ffffffff8112ba04>] shrink_slab+0x154/0x310 : [<ffffffff8112f17a>] balance_pgdat+0x4fa/0x6c0 : [<ffffffff8112f4b8>] kswapd+0x178/0x3d0 : [<ffffffff815df134>] ? __schedule+0x3d4/0x8c0 : [<ffffffff81090410>] ? remove_wait_queue+0x50/0x50 : [<ffffffff8112f340>] ? balance_pgdat+0x6c0/0x6c0 : [<ffffffff8108fb6c>] kthread+0x8c/0xa0 for every page. The proper fix for this is has been posted and is https://lkml.org/lkml/2012/2/10/228 "x86/cpa: Use pte_attrs instead of pte_flags on CPA/set_p.._wb/wc operations." along with a detailed description of the problem and solution. But since that posting has gone nowhere I am proposing this band-aid solution so that at least users don't get the page corruption (the pages that are WC don't get changed to WB and end up being recycled for filesystem or other things causing mysterious crashes). The negative impact of this patch is that users of WC flag (which are InfiniBand, radeon, nouveau drivers) won't be able to set that flag - so they are going to see performance degradation. But stability is more important here. Fixes RH BZ# 742032, 787403, and 745574 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>		13 years ago
..
Kconfig	xen: Make XEN_MAX_DOMAIN_MEMORY have more sensible defaults	13 years ago
Makefile	xen/tracing: Fix tracing config option properly	14 years ago
debugfs.c	switch debugfs to umode_t	13 years ago
debugfs.h	switch debugfs to umode_t	13 years ago
enlighten.c	xen/pat: Disable PAT support for now.	13 years ago
grant-table.c	Merge commit 'v3.2-rc3' into stable/for-linus-3.3	13 years ago
irq.c	arch/x86/xen/irq: Cleanup code/data sections definitions	14 years ago
mmu.c	xen/pat: Disable PAT support for now.	13 years ago
mmu.h	xen: make a pile of mmu pvop functions static	14 years ago
multicalls.c	xen/multicall: move *idx fields to start of mc_buffer	14 years ago
multicalls.h	xen/trace: add multicall tracing	14 years ago
p2m.c	Merge branches 'stable/bug.fixes-3.2' and 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen	13 years ago
pci-swiotlb-xen.c	treewide: fix a few typos in comments	14 years ago
platform-pci-unplug.c	xen:pvhvm: Modpost section mismatch fix	14 years ago
setup.c	Merge branch 'memblock-kill-early_node_map' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/memblock	13 years ago
smp.c	xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic.	13 years ago
spinlock.c	x86: xen: size struct xen_spinlock to always fit in arch_spinlock_t	13 years ago
suspend.c	xen: suspend: add "arch" to pre/post suspend hooks	14 years ago
time.c	Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen	13 years ago
trace.c	xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set	14 years ago
vdso.h	…
vga.c	xen: allow enable use of VGA console on dom0	14 years ago
xen-asm.S	…
xen-asm.h	…
xen-asm_32.S	xen: x86_32: do not enable iterrupts when returning from exception in interrupt context	14 years ago
xen-asm_64.S	…
xen-head.S	x86, asm: Cleanup unnecssary macros in asm-offsets.c	14 years ago
xen-ops.h	Merge branch 'stable/vga.support' into stable/drivers	14 years ago