From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id 1377B8E0002 for ; Thu, 3 Jan 2019 12:15:05 -0500 (EST) Received: by mail-pf1-f200.google.com with SMTP id p9so35222961pfj.3 for ; Thu, 03 Jan 2019 09:15:05 -0800 (PST) Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com. [47.88.44.36]) by mx.google.com with ESMTPS id d15si50467134pgt.498.2019.01.03.09.15.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Jan 2019 09:15:03 -0800 (PST) Subject: Re: [v4 PATCH 2/2] mm: swap: add comment for swap_vma_readahead References: <1546145375-793-1-git-send-email-yang.shi@linux.alibaba.com> <1546145375-793-2-git-send-email-yang.shi@linux.alibaba.com> <875zv6w5m6.fsf@yhuang-dev.intel.com> From: Yang Shi Message-ID: Date: Thu, 3 Jan 2019 09:12:52 -0800 MIME-Version: 1.0 In-Reply-To: <875zv6w5m6.fsf@yhuang-dev.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: owner-linux-mm@kvack.org List-ID: To: "Huang, Ying" Cc: tim.c.chen@intel.com, minchan@kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On 1/2/19 11:41 PM, Huang, Ying wrote: > Yang Shi writes: > >> swap_vma_readahead()'s comment is missed, just add it. >> >> Cc: Huang Ying >> Cc: Tim Chen >> Cc: Minchan Kim >> Signed-off-by: Yang Shi >> --- >> mm/swap_state.c | 17 +++++++++++++++++ >> 1 file changed, 17 insertions(+) >> >> diff --git a/mm/swap_state.c b/mm/swap_state.c >> index 78d500e..dd8f698 100644 >> --- a/mm/swap_state.c >> +++ b/mm/swap_state.c >> @@ -698,6 +698,23 @@ static void swap_ra_info(struct vm_fault *vmf, >> pte_unmap(orig_pte); >> } >> >> +/** >> + * swap_vm_readahead - swap in pages in hope we need them soon > s/swap_vm_readahead/swap_vma_readahead/ > >> + * @entry: swap entry of this memory >> + * @gfp_mask: memory allocation flags >> + * @vmf: fault information >> + * >> + * Returns the struct page for entry and addr, after queueing swapin. >> + * >> + * Primitive swap readahead code. We simply read in a few pages whoes >> + * virtual addresses are around the fault address in the same vma. >> + * >> + * This has been extended to use the NUMA policies from the mm triggering >> + * the readahead. > What is this? I know you copy it from swap_cluster_readahead(), but we > have only one mm for vma readahead. Aha, I see. Actually I was confused by this too, so just copied from swap_cluster_readahead. > >> + * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL. > Better to make it explicit that your are talking about mmap_sem? Sure. Thanks, Yang > > Best Regards, > Huang, Ying > >> + * >> + */ >> static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, >> struct vm_fault *vmf) >> {