Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752890AbYJJEAv (ORCPT ); Fri, 10 Oct 2008 00:00:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750793AbYJJEAn (ORCPT ); Fri, 10 Oct 2008 00:00:43 -0400 Received: from smtp-outbound-2.vmware.com ([65.115.85.73]:44754 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764AbYJJEAm (ORCPT ); Fri, 10 Oct 2008 00:00:42 -0400 Message-ID: <48EED323.3050609@vmware.com> Date: Fri, 10 Oct 2008 11:59:31 +0800 From: bmao User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Yinghai Lu CC: bibo mao , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" Subject: Re: [patch 1/1] combine two adjacent mtrr region with the same type References: <48EE291F.2010704@kernel.org> In-Reply-To: <48EE291F.2010704@kernel.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4323 Lines: 100 Yinghai Lu wrote: > bibo mao wrote: >> This patch is to combine two adjacent mtrr region with the same type. >> >> kernel/cpu/mtrr/main.c | 17 +++++++++++++++-- >> 3 files changed, 15 insertions(+), 2 deletions(-) >> >> Signed-off-by: bibo mao >> >> ------------------------------------------------------------------------------- >> diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c >> index 6e212f3..c3adf83 100644 >> --- a/arch/x86/kernel/cpu/mtrr/main.c >> +++ b/arch/x86/kernel/cpu/mtrr/main.c >> @@ -305,7 +305,7 @@ int mtrr_add_page(unsigned long base, unsigned long size, >> { >> int i, j, replace, error; >> mtrr_type ltype; >> - unsigned long lbase, lsize; >> + unsigned long lbase, lsize, newbase; >> >> if (!mtrr_if) >> return -ENXIO; >> @@ -344,7 +344,7 @@ int mtrr_add_page(unsigned long base, unsigned long size, >> mutex_lock(&mtrr_mutex); >> for (i = 0; i < num_var_ranges; ++i) { >> mtrr_if->get(i, &lbase, &lsize, <ype); >> - if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase) >> + if (!lsize || base > lbase + lsize || base + size < lbase) >> continue; >> /* At this point we know there is some kind of overlap/enclosure */ >> if (base < lbase || base + size - 1 > lbase + lsize - 1) { >> @@ -356,6 +356,19 @@ int mtrr_add_page(unsigned long base, unsigned long size, >> } >> else if (types_compatible(type, ltype)) >> continue; >> + } else if ((base == lbase + lsize) || (lbase ==base + size)) { >> + if (type != ltype) >> + continue; > this path seems not right... > > do you need > > if (ltype != type) { > if (types_compatible(type, ltype)) > continue; > printk (KERN_WARNING "mtrr: type mismatch for %lx000,%lx000 old: %s new: %s\n", > base, size, mtrr_attrib_to_str(ltype), > mtrr_attrib_to_str(type)); > goto out; > } > ? This warning info is for two enclosed mtrr region, but it is adjacent here. Here is no overlapped mtrr region even. > > > > >> + /* New region adjacent with an existing region */ >> + newbase = (base < lbase) ? base : lbase; >> + if (!mtrr_if->validate_add_page(newbase,lsize + size,type) && >> + mtrr_if->get_free_region(newbase, lsize + size, replace)>=0) { >> + base = newbase; >> + size += lsize; >> + replace = i; >> + continue; >> + } else >> + continue; >> } >> printk(KERN_WARNING >> "mtrr: 0x%lx000,0x%lx000 overlaps existing" > > better to have some test case... > > YH > Here is test result: # echo "base=0x02000000 size=0x00800000 type=write-back" >| /proc/mtrr # echo "base=0x03000000 size=0x01000000 type=write-back" >| /proc/mtrr # cat /proc/mtrr reg00: base=0x02000000 ( 32MB), size= 8MB: write-back, count=1 reg01: base=0x03000000 ( 48MB), size= 16MB: write-back, count=1 # echo "base=0x02800000 size=0x00800000 type=write-back" >| /proc/mtrr # cat /proc/mtrr reg01: base=0x02000000 ( 32MB), size= 32MB: write-back, count=3 Without this patch, it will display with this result: reg00: base=0x02000000 ( 32MB), size= 8MB: write-back, count=1 reg01: base=0x03000000 ( 48MB), size= 16MB: write-back, count=1 reg02: base=0x02800000 ( 40MB), size= 8MB: write-back, count=1 thanks bibo,mao -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/