From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1522203053; cv=none; d=google.com; s=arc-20160816; b=azf++A7uv6UcRTW9ZwfiQl5symiUGGkQGtTiwyXWkFoFo1vmDv8+/ITFZjmXlxvOlU RMpONcn+N3/qJCGCK0LRBf0DETTi0ircZHE5bwVjYBHsRAEnmEhlRn3/mfsDFZx5e2KH dDXpJ7WpSxhCbIwAaRCkivyqfonnTKLz5luln/OHmco6YPiEEueb3VgdEMUCecLPVpVm ilkMHFlvq1XGmOyP0yvBWl8m4MSsDA9Rn5j5Ii0IHPtuArLhfd6oygqQoLLVxFGW84ey h3zmcHKdg3CuKT518Ryi+hXZJtHL/fXnFrIwJCdEFcWHJDAU5ExlKXIOe2FjeQIbwWn+ 6mEw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:dkim-signature :arc-authentication-results; bh=pM6Zr7JvJiK2VjNOxIPe2Q1usvS6zA6cJdptKQ73/Ck=; b=nj7dxklwxukTW3a+ngw6mRudEUkI7ssRSQ3VB0j0Rw6XMvWHc6e2ux2EiSvdFt0xnl 2ctG14eDqz85Wq2xiTykc3MJ/kI+ETXjIUGIsSjZDo0n4hzKmYusMD6FSHEh3NXgvkY7 ILQGRrPZfWlehJL3biTt+/AkQHqN7wdXIdTo3812xJ05fVkqWlDaDyJOTKNzG/MvwnbU +pZALy84YFlidj5BghWTi+sRKl4e7R4TTM1JO28rcSTsInUBcsXn9W7Vy6XWWCCApNrY pAuXy82Xd7c2QYtfzFcfNecy5wHPaM/wzoL/lCxLpFQzdaUbo3g2ZSRh9hyVG/QcHy0G LxwA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=gnlxmqh2; spf=pass (google.com: domain of hejianet@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=hejianet@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=gnlxmqh2; spf=pass (google.com: domain of hejianet@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=hejianet@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com X-Google-Smtp-Source: AIpwx48uEsmVYTAyKWQoAV4RBTMH/krBhI0DAp7a0BMIUXWbA5Jse1PSZgPTgtgIlK/r673pifnBaA== Subject: Re: [PATCH v3 5/5] mm: page_alloc: reduce unnecessary binary search in early_pfn_valid() To: Daniel Vacek Cc: Andrew Morton , Michal Hocko , Catalin Marinas , Mel Gorman , Will Deacon , Mark Rutland , Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Pavel Tatashin , Daniel Jordan , AKASHI Takahiro , Gioh Kim , Steven Sistare , Eugeniu Rosca , Vlastimil Babka , open list , linux-mm@kvack.org, James Morse , Steve Capper , x86@kernel.org, Greg Kroah-Hartman , Kate Stewart , Philippe Ombredanne , Johannes Weiner , Kemi Wang , Petr Tesarik , YASUAKI ISHIMATSU , Andrey Ryabinin , Nikolay Borisov , Jia He References: <1522033340-6575-1-git-send-email-hejianet@gmail.com> <1522033340-6575-6-git-send-email-hejianet@gmail.com> From: Jia He Message-ID: <55b15841-bac7-7576-6da8-edff0fe0e9b2@gmail.com> Date: Wed, 28 Mar 2018 10:10:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1595967726824287600?= X-GMAIL-MSGID: =?utf-8?q?1596145588780757615?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 3/28/2018 1:51 AM, Daniel Vacek Wrote: > On Mon, Mar 26, 2018 at 5:02 AM, Jia He wrote: >> Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns >> where possible") optimized the loop in memmap_init_zone(). But there is >> still some room for improvement. E.g. in early_pfn_valid(), if pfn and >> pfn+1 are in the same memblock region, we can record the last returned >> memblock region index and check check pfn++ is still in the same region. >> >> Currently it only improve the performance on arm64 and will have no >> impact on other arches. >> >> Signed-off-by: Jia He >> --- >> arch/x86/include/asm/mmzone_32.h | 2 +- >> include/linux/mmzone.h | 12 +++++++++--- >> mm/page_alloc.c | 2 +- >> 3 files changed, 11 insertions(+), 5 deletions(-) >> >> diff --git a/arch/x86/include/asm/mmzone_32.h b/arch/x86/include/asm/mmzone_32.h >> index 73d8dd1..329d3ba 100644 >> --- a/arch/x86/include/asm/mmzone_32.h >> +++ b/arch/x86/include/asm/mmzone_32.h >> @@ -49,7 +49,7 @@ static inline int pfn_valid(int pfn) >> return 0; >> } >> >> -#define early_pfn_valid(pfn) pfn_valid((pfn)) >> +#define early_pfn_valid(pfn, last_region_idx) pfn_valid((pfn)) >> >> #endif /* CONFIG_DISCONTIGMEM */ >> >> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h >> index d797716..3a686af 100644 >> --- a/include/linux/mmzone.h >> +++ b/include/linux/mmzone.h >> @@ -1267,9 +1267,15 @@ static inline int pfn_present(unsigned long pfn) >> }) >> #else >> #define pfn_to_nid(pfn) (0) >> -#endif >> +#endif /*CONFIG_NUMA*/ >> + >> +#ifdef CONFIG_HAVE_ARCH_PFN_VALID >> +#define early_pfn_valid(pfn, last_region_idx) \ >> + pfn_valid_region(pfn, last_region_idx) >> +#else >> +#define early_pfn_valid(pfn, last_region_idx) pfn_valid(pfn) >> +#endif /*CONFIG_HAVE_ARCH_PFN_VALID*/ >> >> -#define early_pfn_valid(pfn) pfn_valid(pfn) >> void sparse_init(void); >> #else >> #define sparse_init() do {} while (0) >> @@ -1288,7 +1294,7 @@ struct mminit_pfnnid_cache { >> }; >> >> #ifndef early_pfn_valid >> -#define early_pfn_valid(pfn) (1) >> +#define early_pfn_valid(pfn, last_region_idx) (1) >> #endif >> >> void memory_present(int nid, unsigned long start, unsigned long end); >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 0bb0274..debccf3 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -5484,7 +5484,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, >> if (context != MEMMAP_EARLY) >> goto not_early; >> >> - if (!early_pfn_valid(pfn)) { >> + if (!early_pfn_valid(pfn, &idx)) { >> #if (defined CONFIG_HAVE_MEMBLOCK) && (defined CONFIG_HAVE_ARCH_PFN_VALID) >> /* >> * Skip to the pfn preceding the next valid one (or >> -- >> 2.7.4 >> > Hmm, what about making index global variable instead of changing all > the prototypes? Similar to early_pfnnid_cache for example. Something > like: > > #ifdef CONFIG_HAVE_ARCH_PFN_VALID > extern int early_region_idx __meminitdata; > #define early_pfn_valid(pfn) \ > pfn_valid_region(pfn, &early_region_idx) > #else > #define early_pfn_valid(pfn) pfn_valid(pfn) > #endif /*CONFIG_HAVE_ARCH_PFN_VALID*/ > > And move this to arch/arm64/include/asm/page.h ? > > --nX > Yes. ok with me -- Cheers, Jia