From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx158.postini.com [74.125.245.158]) by kanga.kvack.org (Postfix) with SMTP id A12A86B02EB for ; Fri, 3 May 2013 14:49:26 -0400 (EDT) Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 4 May 2013 04:39:46 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 97E1E2CE804A for ; Sat, 4 May 2013 04:49:16 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r43In77723199882 for ; Sat, 4 May 2013 04:49:09 +1000 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r43InD0K030092 for ; Sat, 4 May 2013 04:49:13 +1000 From: "Aneesh Kumar K.V" Subject: Re: [PATCH -V7 08/10] powerpc/THP: Enable THP on PPC64 In-Reply-To: <20130503051528.GT13041@truffula.fritz.box> References: <1367178711-8232-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1367178711-8232-9-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20130503051528.GT13041@truffula.fritz.box> Date: Sat, 04 May 2013 00:19:03 +0530 Message-ID: <87r4hn5274.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: David Gibson Cc: benh@kernel.crashing.org, paulus@samba.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org David Gibson writes: > On Mon, Apr 29, 2013 at 01:21:49AM +0530, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> We enable only if the we support 16MB page size. >> >> Signed-off-by: Aneesh Kumar K.V >> --- >> arch/powerpc/include/asm/pgtable-ppc64.h | 3 +-- >> arch/powerpc/mm/pgtable_64.c | 28 ++++++++++++++++++++++++++++ >> 2 files changed, 29 insertions(+), 2 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h >> index 97fc839..d65534b 100644 >> --- a/arch/powerpc/include/asm/pgtable-ppc64.h >> +++ b/arch/powerpc/include/asm/pgtable-ppc64.h >> @@ -426,8 +426,7 @@ static inline unsigned long pmd_pfn(pmd_t pmd) >> return pmd_val(pmd) >> PTE_RPN_SHIFT; >> } >> >> -/* We will enable it in the last patch */ >> -#define has_transparent_hugepage() 0 >> +extern int has_transparent_hugepage(void); >> #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ >> >> static inline int pmd_young(pmd_t pmd) >> diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c >> index 54216c1..b742d6f 100644 >> --- a/arch/powerpc/mm/pgtable_64.c >> +++ b/arch/powerpc/mm/pgtable_64.c >> @@ -754,6 +754,34 @@ void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, >> return; >> } >> >> +int has_transparent_hugepage(void) >> +{ >> + if (!mmu_has_feature(MMU_FTR_16M_PAGE)) >> + return 0; >> + /* >> + * We support THP only if HPAGE_SHIFT is 16MB. >> + */ >> + if (!HPAGE_SHIFT || (HPAGE_SHIFT != mmu_psize_defs[MMU_PAGE_16M].shift)) >> + return 0; > > Again, THP should not be dependent on the value of HPAGE_SHIFT. Just > checking that mmu_psize_defsz[MMU_PAGE_16M].shift == 24 should be > sufficient (i.e. that 16M hugepages are supported). done + /* + * We support THP only if PMD_SIZE is 16MB. + */ + if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT) + return 0; + /* > >> + /* >> + * We need to make sure that we support 16MB hugepage in a segement >> + * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE >> + * of 64K. >> + */ >> + /* >> + * If we have 64K HPTE, we will be using that by default >> + */ >> + if (mmu_psize_defs[MMU_PAGE_64K].shift && >> + (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1)) >> + return 0; >> + /* >> + * Ok we only have 4K HPTE >> + */ >> + if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1) >> + return 0; > > Except you don't actually support THP on 4K base page size yet. That is 64K linux page size and 4K HPTE . We do support that. The Linux page size part is taken care by Kconfig. > >> + >> + return 1; >> +} >> #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ >> >> pmd_t pmdp_get_and_clear(struct mm_struct *mm, > -aneesh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org