From patchwork Thu Sep 20 17:30:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 10608341 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EDB3215A6 for ; Thu, 20 Sep 2018 17:31:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D12602E2DB for ; Thu, 20 Sep 2018 17:31:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CD6802E33C; Thu, 20 Sep 2018 17:31:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 391C62E3BE for ; Thu, 20 Sep 2018 17:31:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2F4CE8E0005; Thu, 20 Sep 2018 13:31:51 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 2A3DB8E0001; Thu, 20 Sep 2018 13:31:51 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 194608E0005; Thu, 20 Sep 2018 13:31:51 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) by kanga.kvack.org (Postfix) with ESMTP id CD6EF8E0001 for ; Thu, 20 Sep 2018 13:31:50 -0400 (EDT) Received: by mail-pg1-f197.google.com with SMTP id v186-v6so3407195pgb.14 for ; Thu, 20 Sep 2018 10:31:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id:in-reply-to:references:mime-version; bh=Ox5uPeCneET61SfHC85zHaITGI5GJMznmFvV9SsV9a0=; b=aWFIh9frxkhXlwHCTckLaD8D2c2auEToYY+W1pmP8ZZGf58SOrTNfrA69il52kq5iX M1REMJz6Lz28vB6PJ0wtlX5eVVz8GsvUsY8CAeM/+Ts2LhjKJGPnFrCKcV4SykDT6zQ5 fq+RBoyQF1XKinNWNQwsPVfdlwW8lkBV4c2Eqczh6gPhjTDCKqW4YumLPF7hHoegW8zN uGAUxHwypZbrqBfBxk1Kc6INUvzfzN2q5bmzkHNSnobP1drJ11l1+FE5CeOFTq7YnMZ1 lxGyiZamfsq1/3rV9PMeny0uy/+BwNzjUNiKi/VauBPTvgFSSC+WGFAI2A5MUhyAcwgg lE1w== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com X-Gm-Message-State: APzg51C1rAPfNWlB590l0N1SZbUKV1Ic+jE7vZ0JHAD5/t4LMfjwDOVD gEsF8wuoPoOOYhIjbuCPDIC8mkYAYcf4gNxyVSN1AsVrLfV35BD1SN30lrYylzNGyr097KFbrtC Apm1jGWliYwgaEEcj8nq9LbM/1YfbKD6uwPj+tr70p7Ex5CC/N3hX4+YqUEAK/YJnIg== X-Received: by 2002:a62:1605:: with SMTP id 5-v6mr42295144pfw.11.1537464710518; Thu, 20 Sep 2018 10:31:50 -0700 (PDT) X-Google-Smtp-Source: ANB0VdZZ9KXNmzX8U8JgI9MKt56UhF3H0NwgvrDH+Iry73PLADHv4ckvGrYfcZbJJXqAC3K5ow5B X-Received: by 2002:a62:1605:: with SMTP id 5-v6mr42295077pfw.11.1537464709266; Thu, 20 Sep 2018 10:31:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1537464709; cv=none; d=google.com; s=arc-20160816; b=UmtbHoCq23Ah5luK+J/EnkUv0AOcN88cvTELk1OkVH8mNryJr3dDIAEQP78XPbnFaJ iUNgD29y22tBW5LroS77MA9fL9YClDxJDoLnSFVWrbHELUfW03RR3e1ycCLgOpZSKQri dbVBAwuTVPYxMDTTqfl1+iLPYLSBZ1yCVKakM92Mt5X1nT3whvXCz2xT1rZqKZW7cx6Y HA/9d6gxNzXrZ9yXo4sciS1ZTzkFTccLaxSODcY1NBCOB+VgY3a51GyGSAzuOTL0RxXG o1Qu924JOOpqBbr2PSMjgos9U5VUPqZUThFvKIVSnqNl8MlPXpGz54qCoNieveUaHHiS n2dA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:references:in-reply-to:message-id:date:subject:cc:to :from; bh=Ox5uPeCneET61SfHC85zHaITGI5GJMznmFvV9SsV9a0=; b=usqciWUZt1AwF2Q2mKhWeSu1LaQZAV0PsXBSHSzCC201W1LLKfVQEWdUTBwo9Q+7Vw UMnQ4/9qjcuecA97l2dv4aCulvLUfH4ay2y/RO/BF3r9diYRFqsA8sCZz9MRUGDctDKa z0i/EIksN1I0vfp85pml5NO5B2cMsJ/YxJXPWXF3FCdVWb7wt6liXgm3h8WnQMRBn72S wO3/ZCdLPMkDnlSRFBYJ52Fphs2m82CpCYS3nDtMXZ+UPqGWjHHFWLubaqQpWtYM4Acq F/xpxzPcMXl6Id02b/HiLkdB78xxy40l7K9qmSo1q5cwFtXP9Y85ZWeIstL3MQWEIyNV rSEQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com Received: from EX13-EDG-OU-001.vmware.com (ex13-edg-ou-001.vmware.com. [208.91.0.189]) by mx.google.com with ESMTPS id x29-v6si4687310pga.674.2018.09.20.10.31.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 20 Sep 2018 10:31:49 -0700 (PDT) Received-SPF: pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) client-ip=208.91.0.189; Authentication-Results: mx.google.com; spf=pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Thu, 20 Sep 2018 10:31:47 -0700 Received: from sc2-haas01-esx0118.eng.vmware.com (sc2-haas01-esx0118.eng.vmware.com [10.172.44.118]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 6078040691; Thu, 20 Sep 2018 10:31:48 -0700 (PDT) From: Nadav Amit To: Greg Kroah-Hartman , Arnd Bergmann CC: , Xavier Deguillard , Nadav Amit , "Michael S. Tsirkin" , Jason Wang , , Subject: [PATCH v2 15/20] mm/balloon_compaction: suppress allocation warnings Date: Thu, 20 Sep 2018 10:30:21 -0700 Message-ID: <20180920173026.141333-16-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180920173026.141333-1-namit@vmware.com> References: <20180920173026.141333-1-namit@vmware.com> MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-001.vmware.com: namit@vmware.com does not designate permitted sender hosts) 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: X-Virus-Scanned: ClamAV using ClamSMTP There is no reason to print warnings when balloon page allocation fails. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: virtualization@lists.linux-foundation.org Cc: linux-mm@kvack.org Reviewed-by: Xavier Deguillard Signed-off-by: Nadav Amit --- mm/balloon_compaction.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index ef858d547e2d..a6c0efb3544f 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -22,7 +22,8 @@ struct page *balloon_page_alloc(void) { struct page *page = alloc_page(balloon_mapping_gfp_mask() | - __GFP_NOMEMALLOC | __GFP_NORETRY); + __GFP_NOMEMALLOC | __GFP_NORETRY | + __GFP_NOWARN); return page; } EXPORT_SYMBOL_GPL(balloon_page_alloc); From patchwork Thu Sep 20 17:30:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 10608345 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E91E315E8 for ; Thu, 20 Sep 2018 17:31:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE4CC2E3EC for ; Thu, 20 Sep 2018 17:31:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CC1C92E3E4; Thu, 20 Sep 2018 17:31:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5B9A72E36E for ; Thu, 20 Sep 2018 17:31:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8A5548E0001; Thu, 20 Sep 2018 13:31:51 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 6C1608E0004; Thu, 20 Sep 2018 13:31:51 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 589418E0001; Thu, 20 Sep 2018 13:31:51 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 010CF8E0004 for ; Thu, 20 Sep 2018 13:31:50 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id p22-v6so5073438pfj.7 for ; Thu, 20 Sep 2018 10:31:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id:in-reply-to:references:mime-version; bh=NalqpQM7vvC10O1HP4Oq4QYQbGocL9ruPnSSgMk0VLE=; b=fErdqC/QCwpQZhsorlkMO0jsWJ1g7Rr/O6GFayfsBMdUl8lcdM5uweS7oOg1AkoVU/ PEJIuyFb9BE6S70CXKUvEao+S+llybei1Lu6/fe+NMrT/Mcd/FzZmokwZT5U9fMFDgjJ 88xi6L8Q81S0LHQm2c85GPPX86b7gyMvKyHKRsX5W8tkhXdDNgZ+YvyGo0JhfeG0yWP4 78FxqpYf0MkvXZ2rKVMp9s28VuoVBfM+QRZD6FTwEWg7y3x17SLnwhnrQ/yn5ewxNDnQ PZRyjG5L5cnkoTZz8DoVw2RnRaH+xpHDQ9ZcJtjKfsloj7irAgu7FZUPlfHSVpcYenBa IlMw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com X-Gm-Message-State: APzg51Ac0uvX87fnrJrqa2oQyEwHG3+2glAkYWaV6W+dpEl4Kd3Xnxka RYqY5+uJzlAU9AQoKH6UuK85hybcG04D0c3F92u6ktPRRrRE0Saw9K747kAwCH2V3V0zGIrFtzG ZYmWdIyQ6Kg1EGFoG57FZT5qvJsMdhv2i/tMEKlOmutC4qVeSNiIp0QBqR0o616iPwA== X-Received: by 2002:a62:1b41:: with SMTP id b62-v6mr18707271pfb.172.1537464710657; Thu, 20 Sep 2018 10:31:50 -0700 (PDT) X-Google-Smtp-Source: ANB0VdaKP6uUNXSWkE7A40mkb+O2WBdmo1Vg7huzaLr6AoXQh+ZLLo/cMV8IilT1NnePTteO2CVd X-Received: by 2002:a62:1b41:: with SMTP id b62-v6mr18707214pfb.172.1537464709582; Thu, 20 Sep 2018 10:31:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1537464709; cv=none; d=google.com; s=arc-20160816; b=CieHpR1O8LzVKn6RXxARp7OxGpat6jJIGnZukwaU6LXGUGDCHhE8ihIej99ZVqky4U dQkO7Ymahge73txg80I4S8Xmfw0nnMs54jexuQCw1wCTQsyxcOo6NEIZlbg4OHL2xT2V N19z730jbclMqSgpo1RZJJsaNRZdUmznKAlrO/urhcxwe1MTI1yC/2/Df6t1iW/a/MAm q6vU8OTo4Ees/OLNglV12NZBAMrsCsbRz19skKIdtWa5H5xTli+aGh5eAFPB5Lbr3suQ MlgioOQMm+UcHBHrOA4+0KEUil/0zQ+v/cGCmmG/4f4H49cszPIcPJPTKXmLJ9lC5OCA Y+5g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:references:in-reply-to:message-id:date:subject:cc:to :from; bh=NalqpQM7vvC10O1HP4Oq4QYQbGocL9ruPnSSgMk0VLE=; b=dK23AIwk+aC0Vpo+K3M5evjRMQ7L2XOqzIHZSDnAi5ZCu2epJ01aHp/ro7zJ8znUVP +UvhR1AkHW92TUiMhGl6QiORqE0tvOTkpfS4O424hyGnNj4c8xFG+QPH5L5ejFcTauZ3 KcnPRm+1BiO/+rJc4NTlHFavtBpTAJA4w/jKDJiPwWuxDYtvnaFUMkIhVktab4ir6bct tZYjYOVMY/qZYS+xenk/reIpEXLUH4fdERBFVKvnVBCHAyLx30i6ZB+E+JxkGpg7dpc1 P49TCotlnmDJLD/+2cWtV75g4xW7kI5Es3xyLjZGa9O5ZEgw7MmCYO3e0IP+5bKELrJv Urow== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com Received: from EX13-EDG-OU-001.vmware.com (ex13-edg-ou-001.vmware.com. [208.91.0.189]) by mx.google.com with ESMTPS id x29-v6si4687310pga.674.2018.09.20.10.31.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 20 Sep 2018 10:31:49 -0700 (PDT) Received-SPF: pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) client-ip=208.91.0.189; Authentication-Results: mx.google.com; spf=pass (google.com: domain of namit@vmware.com designates 208.91.0.189 as permitted sender) smtp.mailfrom=namit@vmware.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=vmware.com Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Thu, 20 Sep 2018 10:31:47 -0700 Received: from sc2-haas01-esx0118.eng.vmware.com (sc2-haas01-esx0118.eng.vmware.com [10.172.44.118]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 6EC8F4069F; Thu, 20 Sep 2018 10:31:48 -0700 (PDT) From: Nadav Amit To: Greg Kroah-Hartman , Arnd Bergmann CC: , Xavier Deguillard , Nadav Amit , "Michael S. Tsirkin" , Jason Wang , , Subject: [PATCH v2 16/20] mm/balloon_compaction: list interfaces Date: Thu, 20 Sep 2018 10:30:22 -0700 Message-ID: <20180920173026.141333-17-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180920173026.141333-1-namit@vmware.com> References: <20180920173026.141333-1-namit@vmware.com> MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-001.vmware.com: namit@vmware.com does not designate permitted sender hosts) 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: X-Virus-Scanned: ClamAV using ClamSMTP Introduce interfaces for ballooning enqueueing and dequeueing of a list of pages. These interfaces reduce the overhead of storing and restoring IRQs by batching the operations. In addition they do not panic if the list of pages is empty. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: linux-mm@kvack.org Cc: virtualization@lists.linux-foundation.org Reviewed-by: Xavier Deguillard Signed-off-by: Nadav Amit --- include/linux/balloon_compaction.h | 4 + mm/balloon_compaction.c | 139 +++++++++++++++++++++-------- 2 files changed, 105 insertions(+), 38 deletions(-) diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h index 53051f3d8f25..2c5a8e09e413 100644 --- a/include/linux/balloon_compaction.h +++ b/include/linux/balloon_compaction.h @@ -72,6 +72,10 @@ extern struct page *balloon_page_alloc(void); extern void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, struct page *page); extern struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info); +extern void balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, + struct list_head *pages); +extern int balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info, + struct list_head *pages, int n_req_pages); static inline void balloon_devinfo_init(struct balloon_dev_info *balloon) { diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index a6c0efb3544f..b920c2a10d6f 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -10,6 +10,100 @@ #include #include +static int balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info, + struct page *page) +{ + /* + * Block others from accessing the 'page' when we get around to + * establishing additional references. We should be the only one + * holding a reference to the 'page' at this point. + */ + if (!trylock_page(page)) { + WARN_ONCE(1, "balloon inflation failed to enqueue page\n"); + return -EFAULT; + } + list_del(&page->lru); + balloon_page_insert(b_dev_info, page); + unlock_page(page); + __count_vm_event(BALLOON_INFLATE); + return 0; +} + +/** + * balloon_page_list_enqueue() - inserts a list of pages into the balloon page + * list. + * @b_dev_info: balloon device descriptor where we will insert a new page to + * @pages: pages to enqueue - allocated using balloon_page_alloc. + * + * Driver must call it to properly enqueue a balloon pages before definitively + * removing it from the guest system. + */ +void balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, + struct list_head *pages) +{ + struct page *page, *tmp; + unsigned long flags; + + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + list_for_each_entry_safe(page, tmp, pages, lru) + balloon_page_enqueue_one(b_dev_info, page); + spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); +} +EXPORT_SYMBOL_GPL(balloon_page_list_enqueue); + +/** + * balloon_page_list_dequeue() - removes pages from balloon's page list and + * returns a list of the pages. + * @b_dev_info: balloon device decriptor where we will grab a page from. + * @pages: pointer to the list of pages that would be returned to the caller. + * @n_req_pages: number of requested pages. + * + * Driver must call it to properly de-allocate a previous enlisted balloon pages + * before definetively releasing it back to the guest system. This function + * tries to remove @n_req_pages from the ballooned pages and return it to the + * caller in the @pages list. + * + * Note that this function may fail to dequeue some pages temporarily empty due + * to compaction isolated pages. + * + * Return: number of pages that were added to the @pages list. + */ +int balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info, + struct list_head *pages, int n_req_pages) +{ + struct page *page, *tmp; + unsigned long flags; + int n_pages = 0; + + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + list_for_each_entry_safe(page, tmp, &b_dev_info->pages, lru) { + /* + * Block others from accessing the 'page' while we get around + * establishing additional references and preparing the 'page' + * to be released by the balloon driver. + */ + if (!trylock_page(page)) + continue; + + if (IS_ENABLED(CONFIG_BALLOON_COMPACTION) && + PageIsolated(page)) { + /* raced with isolation */ + unlock_page(page); + continue; + } + balloon_page_delete(page); + __count_vm_event(BALLOON_DEFLATE); + unlock_page(page); + list_add(&page->lru, pages); + if (++n_pages >= n_req_pages) + break; + } + spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); + + return n_pages; +} +EXPORT_SYMBOL_GPL(balloon_page_list_dequeue); + /* * balloon_page_alloc - allocates a new page for insertion into the balloon * page list. @@ -44,17 +138,9 @@ void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, { unsigned long flags; - /* - * Block others from accessing the 'page' when we get around to - * establishing additional references. We should be the only one - * holding a reference to the 'page' at this point. - */ - BUG_ON(!trylock_page(page)); spin_lock_irqsave(&b_dev_info->pages_lock, flags); - balloon_page_insert(b_dev_info, page); - __count_vm_event(BALLOON_INFLATE); + balloon_page_enqueue_one(b_dev_info, page); spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); - unlock_page(page); } EXPORT_SYMBOL_GPL(balloon_page_enqueue); @@ -71,36 +157,13 @@ EXPORT_SYMBOL_GPL(balloon_page_enqueue); */ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) { - struct page *page, *tmp; unsigned long flags; - bool dequeued_page; + LIST_HEAD(pages); + int n_pages; - dequeued_page = false; - spin_lock_irqsave(&b_dev_info->pages_lock, flags); - list_for_each_entry_safe(page, tmp, &b_dev_info->pages, lru) { - /* - * Block others from accessing the 'page' while we get around - * establishing additional references and preparing the 'page' - * to be released by the balloon driver. - */ - if (trylock_page(page)) { -#ifdef CONFIG_BALLOON_COMPACTION - if (PageIsolated(page)) { - /* raced with isolation */ - unlock_page(page); - continue; - } -#endif - balloon_page_delete(page); - __count_vm_event(BALLOON_DEFLATE); - unlock_page(page); - dequeued_page = true; - break; - } - } - spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); + n_pages = balloon_page_list_dequeue(b_dev_info, &pages, 1); - if (!dequeued_page) { + if (n_pages != 1) { /* * If we are unable to dequeue a balloon page because the page * list is empty and there is no isolated pages, then something @@ -113,9 +176,9 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) !b_dev_info->isolated_pages)) BUG(); spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); - page = NULL; + return NULL; } - return page; + return list_first_entry(&pages, struct page, lru); } EXPORT_SYMBOL_GPL(balloon_page_dequeue);