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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DC12ECDE3D for ; Fri, 19 Oct 2018 17:35:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 678DB2087A for ; Fri, 19 Oct 2018 17:35:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="syXSz+ry" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 678DB2087A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727983AbeJTBm7 (ORCPT ); Fri, 19 Oct 2018 21:42:59 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:46778 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727501AbeJTBm6 (ORCPT ); Fri, 19 Oct 2018 21:42:58 -0400 Received: by mail-lf1-f65.google.com with SMTP id p143-v6so14796140lfp.13 for ; Fri, 19 Oct 2018 10:35:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=QOpxQtsqnZO1O69woFc9jT6MsNTDcWqgsVf/VQ7puy8=; b=syXSz+rynUT0XXnSrP7QxmpOFvRr5Bfr0xP2NEUQePfz5z37UIDck093aaGr+Jxa4v EIInTHwHm0Q1NDl5tr94Fdjbza1caupFFHFKQVtbRprJ360q4FOBCZ13lGxR4Zf+HMxQ 094PnyXuCxKdPliwGRChjlwkjH/W/vP9duBjC07du/+d5V8+x2QdLY3kZaPjdshVJdVP mh7t5Ai8b+R+dVx7nyy1No4zBKV5LFDhL/DjNTVsa9XiKP8BHHkRrRYw72bQ2wMQIHVv bGpn8T5tGgIOlqUQy7B5X1gv9wggtCiGwjIPj9TcxxaN8O1vYv1Sexy5i8ne01YMXcxG VupA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=QOpxQtsqnZO1O69woFc9jT6MsNTDcWqgsVf/VQ7puy8=; b=WLQXZElCAfJWJeObH4/n07gqH21AECqYqoOVBiycOqvl/fKvFQgO5/V4UBsDfOa5Qw li7UQHsRlcfCS4XdTsFsQXX6U/GHlXXI2QWgYBPhclSKRLZ6IF+sKk0OTFvhwgT/ZcZ+ mpC1CkRv1wMYT9Q6fcmII7QjzeZTA1JiLOWWMuVyLeNKzS9waCZEGoRGZagTFQD4gvVc 5ZmNZQdBrO0WyV3nV7GRzB4d2D0dHdn+M5dH4catv+GmnTDwyXJTQrp7MDltvazwGzgZ y8fEjVcldrKMIZ1h3adU4wPIfVDD2NbmCw/q/PL16kSgB/Oa3FGbYdQXMLrnzY4leKGS SUSQ== X-Gm-Message-State: ABuFfojOexhyuj9nfBDYagBn9vUBK/oZvGkgu6/KJl5rW1LV4ZUADOEI vE7j3o3eGpDEbHd15DK2c1o= X-Google-Smtp-Source: ACcGV61jzkETd02239M3JQrg7GcoPJDUVxeCvyghNY325cP/LpZXE8bIG+qEVdYd9SXYWUownIJSJg== X-Received: by 2002:a19:a501:: with SMTP id o1-v6mr3480817lfe.41.1539970553327; Fri, 19 Oct 2018 10:35:53 -0700 (PDT) Received: from pc636.semobile.internal ([37.139.158.167]) by smtp.gmail.com with ESMTPSA id k9-v6sm5531530lje.51.2018.10.19.10.35.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 19 Oct 2018 10:35:52 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: Matthew Wilcox , Andrew Morton , linux-mm@kvack.org Cc: LKML , Michal Hocko , Thomas Garnier , Oleksiy Avramchenko , Steven Rostedt , Joel Fernandes , Thomas Gleixner , Ingo Molnar , Tejun Heo , "Uladzislau Rezki (Sony)" Subject: [RFC PATCH 2/2] mm: add priority threshold to __purge_vmap_area_lazy() Date: Fri, 19 Oct 2018 19:35:38 +0200 Message-Id: <20181019173538.590-3-urezki@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181019173538.590-1-urezki@gmail.com> References: <20181019173538.590-1-urezki@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 763b218ddfaf ("mm: add preempt points into __purge_vmap_area_lazy()") introduced some preempt points, one of those is making an allocation more prioritized. Prioritizing an allocation over freeing does not work well all the time, i.e. it should be rather a compromise. 1) Number of lazy pages directly influence on busy list length thus on operations like: allocation, lookup, unmap, remove, etc. 2) Under heavy simultaneous allocations/releases there may be a situation when memory usage grows too fast hitting out_of_memory -> panic. Establish a threshold passing which the freeing path is prioritized over allocation creating a balance between both. Signed-off-by: Uladzislau Rezki (Sony) --- mm/vmalloc.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a7f257540a05..bbafcff6632b 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1124,23 +1124,23 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) struct llist_node *valist; struct vmap_area *va; struct vmap_area *n_va; - bool do_free = false; + int resched_threshold; lockdep_assert_held(&vmap_purge_lock); valist = llist_del_all(&vmap_purge_list); + if (unlikely(valist == NULL)) + return false; + llist_for_each_entry(va, valist, purge_list) { if (va->va_start < start) start = va->va_start; if (va->va_end > end) end = va->va_end; - do_free = true; } - if (!do_free) - return false; - flush_tlb_kernel_range(start, end); + resched_threshold = (int) lazy_max_pages() << 1; spin_lock(&vmap_area_lock); llist_for_each_entry_safe(va, n_va, valist, purge_list) { @@ -1148,7 +1148,9 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) __free_vmap_area(va); atomic_sub(nr, &vmap_lazy_nr); - cond_resched_lock(&vmap_area_lock); + + if (atomic_read(&vmap_lazy_nr) < resched_threshold) + cond_resched_lock(&vmap_area_lock); } spin_unlock(&vmap_area_lock); return true; -- 2.11.0