From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by kanga.kvack.org (Postfix) with ESMTP id 313216B00E9 for ; Mon, 11 Nov 2013 20:23:07 -0500 (EST) Received: by mail-pb0-f54.google.com with SMTP id ro12so2925098pbb.27 for ; Mon, 11 Nov 2013 17:23:06 -0800 (PST) Received: from psmtp.com ([74.125.245.128]) by mx.google.com with SMTP id bf6si6370012pad.77.2013.11.11.17.23.04 for ; Mon, 11 Nov 2013 17:23:05 -0800 (PST) Message-ID: <528182F6.4070308@codeaurora.org> Date: Mon, 11 Nov 2013 17:23:02 -0800 From: Laura Abbott MIME-Version: 1.0 Subject: Re: [RFC PATCH 3/4] mm/vmalloc.c: Allow lowmem to be tracked in vmalloc References: <1384212412-21236-1-git-send-email-lauraa@codeaurora.org> <1384212412-21236-4-git-send-email-lauraa@codeaurora.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Kyungmin Park Cc: linux-mm@kvack.org, Neeti Desai , linux-arm-kernel@lists.infradead.org On 11/11/2013 3:37 PM, Kyungmin Park wrote: > Hi Laura, > > On Tue, Nov 12, 2013 at 8:26 AM, Laura Abbott wrote: >> vmalloc is currently assumed to be a completely separate address space >> from the lowmem region. While this may be true in the general case, >> there are some instances where lowmem and virtual space intermixing >> provides gains. One example is needing to steal a large chunk of physical >> lowmem for another purpose outside the systems usage. Rather than >> waste the precious lowmem space on a 32-bit system, we can allow the >> virtual holes created by the physical holes to be used by vmalloc >> for virtual addressing. Track lowmem allocations in vmalloc to >> allow mixing of lowmem and vmalloc. >> >> Signed-off-by: Laura Abbott >> Signed-off-by: Neeti Desai >> --- >> include/linux/mm.h | 6 ++++++ >> include/linux/vmalloc.h | 1 + >> mm/Kconfig | 11 +++++++++++ >> mm/vmalloc.c | 26 ++++++++++++++++++++++++++ >> 4 files changed, 44 insertions(+), 0 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index f022460..76df50d 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -308,6 +308,10 @@ unsigned long vmalloc_to_pfn(const void *addr); >> * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there >> * is no special casing required. >> */ >> + >> +#ifdef CONFIG_VMALLOC_SAVING > mismatch below Kconfig. CONFIG_ENABLE_VMALLOC_SAVING? Argh, I folded in a wrong patch when integrating. I'll fix it. >> +extern int is_vmalloc_addr(const void *x) >> +#else >> static inline int is_vmalloc_addr(const void *x) >> { >> #ifdef CONFIG_MMU >> @@ -318,6 +322,8 @@ static inline int is_vmalloc_addr(const void *x) >> return 0; >> #endif >> } >> +#endif >> + >> #ifdef CONFIG_MMU >> extern int is_vmalloc_or_module_addr(const void *x); >> #else >> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h >> index 4b8a891..e0c8c49 100644 >> --- a/include/linux/vmalloc.h >> +++ b/include/linux/vmalloc.h >> @@ -16,6 +16,7 @@ struct vm_area_struct; /* vma defining user mapping in mm_types.h */ >> #define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */ >> #define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */ >> #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */ >> +#define VM_LOWMEM 0x00000040 /* Tracking of direct mapped lowmem */ >> /* bits [20..32] reserved for arch specific ioremap internals */ >> >> /* >> diff --git a/mm/Kconfig b/mm/Kconfig >> index 8028dcc..b3c459d 100644 >> --- a/mm/Kconfig >> +++ b/mm/Kconfig >> @@ -519,3 +519,14 @@ config MEM_SOFT_DIRTY >> it can be cleared by hands. >> >> See Documentation/vm/soft-dirty.txt for more details. >> + >> +config ENABLE_VMALLOC_SAVING >> + bool "Intermix lowmem and vmalloc virtual space" >> + depends on ARCH_TRACKS_VMALLOC >> + help >> + Some memory layouts on embedded systems steal large amounts >> + of lowmem physical memory for purposes outside of the kernel. >> + Rather than waste the physical and virtual space, allow the >> + kernel to use the virtual space as vmalloc space. >> + >> + If unsure, say N. >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> index 13a5495..c7b138b 100644 >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -204,6 +204,29 @@ static int vmap_page_range(unsigned long start, unsigned long end, >> return ret; >> } >> >> +#ifdef ENABLE_VMALLOC_SAVING > missing "CONFIG_" > Yes, this is a mess and needs to be cleaned up. > Thank you, > Kyungimn Park Thanks, Laura -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- 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