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authorYinghai Lu <yhlu.kernel.send@gmail.com>2008-04-29 06:52:33 -0400
committerThomas Gleixner <tglx@linutronix.de>2008-05-25 04:55:09 -0400
commit95ffa2438d0e9c48779f0106b1c0eb36165e759c (patch)
tree63829c04435fd99fb655a0d1b94fbd2094549ceb /Documentation
parent0dbfafa5fcd4dd189e2adc7b6ed9e0405e846d79 (diff)
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')
-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
599 See drivers/char/README.epca and 599 See drivers/char/README.epca and
600 Documentation/digiepca.txt. 600 Documentation/digiepca.txt.
601 601
602 disable_mtrr_cleanup [X86]
603 enable_mtrr_cleanup [X86]
604 The kernel tries to adjust MTRR layout from continuous
605 to discrete, to make X server driver able to add WB
606 entry later. This parameter enables/disables that.
607
608 mtrr_chunk_size=nn[KMG] [X86]
609 used for mtrr cleanup. It is largest continous chunk
610 that could hold holes aka. UC entries.
611
612 mtrr_gran_size=nn[KMG] [X86]
613 used for mtrr cleanup. It is granity of mtrr block.
614 Big value could prevent small alignment use up MTRRs.
615
602 disable_mtrr_trim [X86, Intel and AMD only] 616 disable_mtrr_trim [X86, Intel and AMD only]
603 By default the kernel will trim any uncacheable 617 By default the kernel will trim any uncacheable
604 memory out of your available memory pool based on 618 memory out of your available memory pool based on