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authorYinghai Lu <yhlu.kernel.send@gmail.com>2008-04-29 14:52:33 +0400
committerThomas Gleixner <tglx@linutronix.de>2008-05-25 12:55:09 +0400
commit95ffa2438d0e9c48779f0106b1c0eb36165e759c (patch)
tree63829c04435fd99fb655a0d1b94fbd2094549ceb /Documentation/kernel-parameters.txt
parent0dbfafa5fcd4dd189e2adc7b6ed9e0405e846d79 (diff)
downloadlinux-95ffa2438d0e9c48779f0106b1c0eb36165e759c.tar.xz
x86: mtrr cleanup for converting continuous to discrete layout, v8
some BIOS like to use continus MTRR layout, and X driver can not add WB entries for graphical cards when 4g or more RAM installed. the patch will change MTRR to discrete. mtrr_chunk_size= could be used to have smaller continuous block to hold holes. default is 256m, could be set according to size of graphics card memory. mtrr_gran_size= could be used to send smallest mtrr block to avoid run out of MTRRs v2: fix -1 for UC checking v3: default to disable, and need use enable_mtrr_cleanup to enable this feature skip the var state change warning. remove next_basek in range_to_mtrr() v4: correct warning mask. v5: CONFIG_MTRR_SANITIZER v6: fix 1g, 2g, 512 aligment with extra hole v7: gran_sizek to prevent running out of MTRRs. v8: fix hole_basek caculation caused when removing next_basek gran_sizek using when basek is 0. need to apply [PATCH] x86: fix trimming e820 with MTRR holes. right after this one. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt14
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e07c432c731f..44427607b7c6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -599,6 +599,20 @@ and is between 256 and 4096 characters. It is defined in the file
See drivers/char/README.epca and
Documentation/digiepca.txt.
+ disable_mtrr_cleanup [X86]
+ enable_mtrr_cleanup [X86]
+ The kernel tries to adjust MTRR layout from continuous
+ to discrete, to make X server driver able to add WB
+ entry later. This parameter enables/disables that.
+
+ mtrr_chunk_size=nn[KMG] [X86]
+ used for mtrr cleanup. It is largest continous chunk
+ that could hold holes aka. UC entries.
+
+ mtrr_gran_size=nn[KMG] [X86]
+ used for mtrr cleanup. It is granity of mtrr block.
+ Big value could prevent small alignment use up MTRRs.
+
disable_mtrr_trim [X86, Intel and AMD only]
By default the kernel will trim any uncacheable
memory out of your available memory pool based on