From 95ffa2438d0e9c48779f0106b1c0eb36165e759c Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 29 Apr 2008 03:52:33 -0700 Subject: 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 Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- Documentation/kernel-parameters.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'Documentation') 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 -- cgit v1.2.3 From 12031a624af7816ec7660b82be648aa3703b4ebe Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 2 May 2008 02:40:22 -0700 Subject: x86: mtrr cleanup for converting continuous to discrete - auto detect v4 Loop through mtrr chunk_size and gran_size from 1M to 2G to find out the optimal value so user does not need to add mtrr_chunk_size and mtrr_gran_size to the kernel command line. If optimal value is not found, print out all list to help select less optimal value. Add mtrr_spare_reg_nr= so user could set 2 instead of 1, if the card need more entries. v2: find the one with more spare entries v3: fix hole_basek offset v4: tight the compare between range and range_new loop stop with 4g Signed-off-by: Yinghai Lu Cc: Andrew Morton Cc: Gabriel C Cc: Mika Fischer Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 44427607b7c6..2000977af776 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -610,8 +610,17 @@ and is between 256 and 4096 characters. It is defined in the file 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. + Used for mtrr cleanup. It is granularity of mtrr block. + Default is 1. + Large value could prevent small alignment from + using up MTRRs. + + mtrr_spare_reg_nr=n [X86] + Format: + Range: 0,7 : spare reg number + Default : 1 + Used for mtrr cleanup. It is spare mtrr entries number. + Set to 2 or more if your graphical card needs more. disable_mtrr_trim [X86, Intel and AMD only] By default the kernel will trim any uncacheable -- cgit v1.2.3