From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zRKJX6SfpzDq8c for ; Wed, 24 Jan 2018 20:15:24 +1100 (AEDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0O9EiPd115731 for ; Wed, 24 Jan 2018 04:15:22 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0b-001b2d01.pphosted.com with ESMTP id 2fpptb1ap7-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 24 Jan 2018 04:15:21 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 24 Jan 2018 02:15:21 -0700 Subject: Re: [PATCH v3 5/5] powerpc/mm: Fix growth direction for hugepages mmaps with slice To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Scott Wood Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: <6920f6efe2dcdabf59350b2d31ee6bd4bdef57f4.1516783089.git.christophe.leroy@c-s.fr> <362a93307a09b521878c47a8999a39a228184293.1516783089.git.christophe.leroy@c-s.fr> From: "Aneesh Kumar K.V" Date: Wed, 24 Jan 2018 14:45:12 +0530 MIME-Version: 1.0 In-Reply-To: <362a93307a09b521878c47a8999a39a228184293.1516783089.git.christophe.leroy@c-s.fr> Content-Type: text/plain; charset=utf-8; format=flowed Message-Id: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 01/24/2018 02:32 PM, Christophe Leroy wrote: > An application running with libhugetlbfs fails to allocate > additional pages to HEAP due to the hugemap being done > inconditionally as topdown mapping: > > mmap(0x10080000, 1572864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0) = 0x73e80000 > [...] > mmap(0x74000000, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0x180000) = 0x73d80000 > munmap(0x73d80000, 1048576) = 0 > [...] > mmap(0x74000000, 1572864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0x180000) = 0x73d00000 > munmap(0x73d00000, 1572864) = 0 > [...] > mmap(0x74000000, 1572864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0x180000) = 0x73d00000 > munmap(0x73d00000, 1572864) = 0 > [...] > > As one can see from the above strace log, mmap() allocates further > pages below the initial one because no space is available on top of it. > > This patch fixes it by requesting bottomup mapping as the non > generic hugetlb_get_unmapped_area() does > > Fixes: d0f13e3c20b6f ("[POWERPC] Introduce address space "slices" ") > Signed-off-by: Christophe Leroy > --- > v3: Was a standalone patch before, but conflicts with this serie. > > arch/powerpc/mm/hugetlbpage.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c > index 79e1378ee303..368ea6b248ad 100644 > --- a/arch/powerpc/mm/hugetlbpage.c > +++ b/arch/powerpc/mm/hugetlbpage.c > @@ -558,7 +558,7 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, > return radix__hugetlb_get_unmapped_area(file, addr, len, > pgoff, flags); > #endif > - return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1); > + return slice_get_unmapped_area(addr, len, flags, mmu_psize, 0); > } > #endif Why make this change also for PPC64? Can you do this #ifdef 8xx?.You can ideally move hugetlb_get_unmapped_area to slice.h and then make this much simpler for 8xxx? -aneesh -aneesh