From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3A6DC38159 for ; Wed, 18 Jan 2023 14:04:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 41D5F6B0074; Wed, 18 Jan 2023 09:04:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D8A76B0075; Wed, 18 Jan 2023 09:04:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 26DFF6B0078; Wed, 18 Jan 2023 09:04:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 1757A6B0074 for ; Wed, 18 Jan 2023 09:04:07 -0500 (EST) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id E135E404B1 for ; Wed, 18 Jan 2023 14:04:06 +0000 (UTC) X-FDA: 80368088892.29.FD9DC0D Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf08.hostedemail.com (Postfix) with ESMTP id DE606160026 for ; Wed, 18 Jan 2023 14:03:56 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ENGv7zjn; spf=pass (imf08.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674050639; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=SPGQBg9MgduKKgBYZco3Nv67NZ90hWX2DplPWeCSJ94=; b=VWaK/mbgYU3A94KWCdR8Rmu0d6NY2pLNNSKFUOMczDRIPhE31rTuuI3pQClXlXdQR+IYcD fHiPkzXf9vdBr+zMqxgm+jQquRfZC2N4ByUljWcmGFOx9YHgAYz38/QGZdVnwMxHUABrdP f8EEvDB0ABlCK0GLXDF0lFps1hWccjM= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ENGv7zjn; spf=pass (imf08.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674050639; a=rsa-sha256; cv=none; b=JF2qVsRR+2VQ+4lfDcJyWCYx8fpCg9dNj98oeYSrOZm5tNOmQMj8wRQQHKhq+3JrZze2Fc 20jdGf4wIXA5VhslRiFfIC8bHqbT57gR+9NNhRKzuurqGoOsl6UZsPi8Sis6SQ9V/Xtn65 ucsj+Kff8DpQxAswH4myZVibMTxEzVc= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674050624; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SPGQBg9MgduKKgBYZco3Nv67NZ90hWX2DplPWeCSJ94=; b=ENGv7zjngdLc/tvTkl/VRMq1+Cs39mwDTXF4Nf9j/bhXlRpLkyABuqUqlj79MtijJ6K7Ez FQlqDwGlG4sGK+K4haP4oM+qflXcEL+rUgqnk9knVmnC9qKC544bKXFtULyoSlbFOXvFDT Z0ZlRR28WFDPBcFPcHcJ/ONMZndqmsg= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-321-olRVNkjHOBe7rcN8dxVa0Q-1; Wed, 18 Jan 2023 09:03:40 -0500 X-MC-Unique: olRVNkjHOBe7rcN8dxVa0Q-1 Received: by mail-wr1-f69.google.com with SMTP id e29-20020adf9bdd000000b002bb0d0ea681so6972686wrc.20 for ; Wed, 18 Jan 2023 06:03:40 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=SPGQBg9MgduKKgBYZco3Nv67NZ90hWX2DplPWeCSJ94=; b=LUUzYLezjSScUJIt4XcFHhjlwa/bRdJAvD44aY+1xO1b/9VzY7O+oHBYYhBSU8ckcw LWc6rN2SdQvGFmx0Umk56FvN5g7+VJstkTVWh7kD1H3n0UKmRpgUNzgZD3WmrZewreq0 P0ZFYcIKUqWDMQ0uP1pnn8w+HYOqtKMasj/QBhgMPnB4AGedxdIc4GgTB1ubeVjf2aJk nsZd+zexhDiuyJ95U3NcMf4Kunr+AQCaoPmDr7prEJqEG94s/yJBBtIC5naxtiSQDGjp xU7tPleE2YMcT24rYsa8yUpuSSIK7nKtWrt0zNzrSkF6LZZUgi3A8fXcVWv4wJWWtOPT /ALA== X-Gm-Message-State: AFqh2kq1SY5aEli+bL4uKgFl26Jv4cKAaGpGkSk5Y8BbpHOEvCivlzOY coT7SlYCMqgxCnduU/BH3A6F0xVpIb8CdiWzv7U+xb4ya7cYjS2Ow20ybC8UzRkixVgus4qUqrb LFXjCnPyaKiU= X-Received: by 2002:a05:600c:6014:b0:3da:2032:6c0f with SMTP id az20-20020a05600c601400b003da20326c0fmr15387776wmb.31.1674050619859; Wed, 18 Jan 2023 06:03:39 -0800 (PST) X-Google-Smtp-Source: AMrXdXubNs3zOMyVlXkvDDI43dE8RHNv9oeecf0SPH6HxZFoiy0PaZvJ2yugphCYiBNu97JGdbffZg== X-Received: by 2002:a05:600c:6014:b0:3da:2032:6c0f with SMTP id az20-20020a05600c601400b003da20326c0fmr15387751wmb.31.1674050619543; Wed, 18 Jan 2023 06:03:39 -0800 (PST) Received: from ?IPV6:2003:cb:c705:800:1a88:f98a:d223:c454? (p200300cbc70508001a88f98ad223c454.dip0.t-ipconnect.de. [2003:cb:c705:800:1a88:f98a:d223:c454]) by smtp.gmail.com with ESMTPSA id i18-20020a05600c355200b003d9df9e59c4sm2440796wmq.37.2023.01.18.06.03.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Jan 2023 06:03:39 -0800 (PST) Message-ID: <0e0c90a2-d12c-f965-9cce-ecd5d28c09dd@redhat.com> Date: Wed, 18 Jan 2023 15:03:38 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item To: yang.yang29@zte.com.cn, akpm@linux-foundation.org Cc: imbrenda@linux.ibm.com, jiang.xuexin@zte.com.cn, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ran.xiaokai@zte.com.cn, xu.xin.sc@gmail.com, xu.xin16@zte.com.cn References: <202212300912449061763@zte.com.cn> From: David Hildenbrand Organization: Red Hat In-Reply-To: <202212300912449061763@zte.com.cn> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: yhxk8y36dwcwuti84izm6ohot4fuwimi X-Rspamd-Queue-Id: DE606160026 X-HE-Tag: 1674050636-257433 X-HE-Meta: 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 nx/2D8ZM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 30.12.22 02:12, yang.yang29@zte.com.cn wrote: > From: xu xin > > A new function try_to_get_old_rmap_item is abstracted from > get_next_rmap_item. This function will be reused by the subsequent > patches about counting ksm_zero_pages. > > The patch improves the readability and reusability of KSM code. > > Signed-off-by: xu xin > Cc: David Hildenbrand > Cc: Claudio Imbrenda > Cc: Xuexin Jiang > Reviewed-by: Xiaokai Ran > Reviewed-by: Yang Yang > --- > mm/ksm.c | 25 +++++++++++++++++++------ > 1 file changed, 19 insertions(+), 6 deletions(-) > > diff --git a/mm/ksm.c b/mm/ksm.c > index 83e2f74ae7da..5b0a7343ff4a 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -2214,23 +2214,36 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite > } > } > > -static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot, > - struct ksm_rmap_item **rmap_list, > - unsigned long addr) > +static struct ksm_rmap_item *try_to_get_old_rmap_item(unsigned long addr, > + struct ksm_rmap_item **rmap_list) > { > - struct ksm_rmap_item *rmap_item; > - > while (*rmap_list) { > - rmap_item = *rmap_list; > + struct ksm_rmap_item *rmap_item = *rmap_list; Empty line missing. > if ((rmap_item->address & PAGE_MASK) == addr) > return rmap_item; > if (rmap_item->address > addr) > break; > *rmap_list = rmap_item->rmap_list; > + /* Running here indicates it's vma has been UNMERGEABLE */ "If we end up here, the VMA is UNMERGEABLE." Although I am not sure if that is true? > remove_rmap_item_from_tree(rmap_item); > free_rmap_item(rmap_item); > } > > + return NULL; > +} > + > +static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot, > + struct ksm_rmap_item **rmap_list, > + unsigned long addr) > +{ > + struct ksm_rmap_item *rmap_item; > + > + /* lookup if we have a old rmap_item matching the addr*/ I suggest dropping that comment, "try_to_get_old_rmap_item()" is expressive enough. > + rmap_item = try_to_get_old_rmap_item(addr, rmap_list); > + if (rmap_item) > + return rmap_item; > + > + /* Need to allocate a new rmap_item */ I suggest dropping that comment for the same reason. > rmap_item = alloc_rmap_item(); > if (rmap_item) { > /* It has already been zeroed */ -- Thanks, David / dhildenb