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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 9ED37CA9ECB for ; Thu, 31 Oct 2019 14:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 690A22087F for ; Thu, 31 Oct 2019 14:30:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cJC83TYz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728252AbfJaOaa (ORCPT ); Thu, 31 Oct 2019 10:30:30 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:57016 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728144AbfJaOa3 (ORCPT ); Thu, 31 Oct 2019 10:30:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572532228; 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=AeVe0KaIImcMvsA2zdCbPU6IJySLMRv/7lmH02hn0Zk=; b=cJC83TYz2Ngn2ylY0NUGfmYtxpESdy4woMUFaB8kR32+/cEBFxa21bIUWOV+c0+GwF2+Tk 2rGftjAGSvf9UyIhUeipcLqyo5Cv1iGHxOWzY7MjKgkXBfmibPbv4ENfqc2eoNKX5zQsWX c9Wj8QWBPsrCwAa6aS0rv++Clc9x4dk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-195-XjGab2tQP0mO-FypSObiTg-1; Thu, 31 Oct 2019 10:30:23 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 35EA82EDC; Thu, 31 Oct 2019 14:30:22 +0000 (UTC) Received: from t460s.redhat.com (unknown [10.36.118.44]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9F0D75D6D6; Thu, 31 Oct 2019 14:30:19 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Andrew Morton , David Hildenbrand , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Pavel Tatashin , Richard Fontana , Allison Randal , Thomas Gleixner , Arun KS Subject: [PATCH v1 07/12] powerpc/pseries: CMM: Convert loaned_pages to an atomic_long_t Date: Thu, 31 Oct 2019 15:29:28 +0100 Message-Id: <20191031142933.10779-8-david@redhat.com> In-Reply-To: <20191031142933.10779-1-david@redhat.com> References: <20191031142933.10779-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: XjGab2tQP0mO-FypSObiTg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When switching to balloon compaction, we want to drop the cmm_lock and completely rely on the balloon compaction list lock internally. loaned_pages is currently protected under the cmm_lock. Note: Right now cmm_alloc_pages() and cmm_free_pages() can be called at the same time, e.g., via the thread and a concurrent OOM notifier. Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Andrew Morton Cc: Pavel Tatashin Cc: Richard Fontana Cc: Allison Randal Cc: Thomas Gleixner Cc: Arun KS Signed-off-by: David Hildenbrand --- arch/powerpc/platforms/pseries/cmm.c | 35 +++++++++++++++------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/= pseries/cmm.c index 29416b621189..3a55dd1fdd39 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -73,7 +73,7 @@ MODULE_PARM_DESC(debug, "Enable module debugging logging.= Set to 1 to enable. " =20 #define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__)= ; } =20 -static unsigned long loaned_pages; +static atomic_long_t loaned_pages; static unsigned long loaned_pages_target; static unsigned long oom_freed_pages; =20 @@ -159,7 +159,7 @@ static long cmm_alloc_pages(long nr) =09=09} =20 =09=09list_add(&page->lru, &cmm_page_list); -=09=09loaned_pages++; +=09=09atomic_long_inc(&loaned_pages); =09=09adjust_managed_page_count(page, -1); =09=09spin_unlock(&cmm_lock); =09=09nr--; @@ -189,7 +189,7 @@ static long cmm_free_pages(long nr) =09=09list_del(&page->lru); =09=09adjust_managed_page_count(page, 1); =09=09__free_page(page); -=09=09loaned_pages--; +=09=09atomic_long_dec(&loaned_pages); =09=09nr--; =09} =09spin_unlock(&cmm_lock); @@ -214,7 +214,7 @@ static int cmm_oom_notify(struct notifier_block *self, =20 =09cmm_dbg("OOM processing started\n"); =09nr =3D cmm_free_pages(nr); -=09loaned_pages_target =3D loaned_pages; +=09loaned_pages_target =3D atomic_long_read(&loaned_pages); =09*freed +=3D KB2PAGES(oom_kb) - nr; =09oom_freed_pages +=3D KB2PAGES(oom_kb) - nr; =09cmm_dbg("OOM processing complete\n"); @@ -231,10 +231,11 @@ static int cmm_oom_notify(struct notifier_block *self= , **/ static void cmm_get_mpp(void) { +=09const long __loaned_pages =3D atomic_long_read(&loaned_pages); +=09const long total_pages =3D totalram_pages() + __loaned_pages; =09int rc; =09struct hvcall_mpp_data mpp_data; =09signed long active_pages_target, page_loan_request, target; -=09signed long total_pages =3D totalram_pages() + loaned_pages; =09signed long min_mem_pages =3D (min_mem_mb * 1024 * 1024) / PAGE_SIZE; =20 =09rc =3D h_get_mpp(&mpp_data); @@ -243,7 +244,7 @@ static void cmm_get_mpp(void) =09=09return; =20 =09page_loan_request =3D div_s64((s64)mpp_data.loan_request, PAGE_SIZE); -=09target =3D page_loan_request + (signed long)loaned_pages; +=09target =3D page_loan_request + __loaned_pages; =20 =09if (target < 0 || total_pages < min_mem_pages) =09=09target =3D 0; @@ -264,7 +265,7 @@ static void cmm_get_mpp(void) =09loaned_pages_target =3D target; =20 =09cmm_dbg("delta =3D %ld, loaned =3D %lu, target =3D %lu, oom =3D %lu, to= talram =3D %lu\n", -=09=09page_loan_request, loaned_pages, loaned_pages_target, +=09=09page_loan_request, __loaned_pages, loaned_pages_target, =09=09oom_freed_pages, totalram_pages()); } =20 @@ -282,6 +283,7 @@ static struct notifier_block cmm_oom_nb =3D { static int cmm_thread(void *dummy) { =09unsigned long timeleft; +=09long __loaned_pages; =20 =09while (1) { =09=09timeleft =3D msleep_interruptible(delay * 1000); @@ -312,11 +314,12 @@ static int cmm_thread(void *dummy) =20 =09=09cmm_get_mpp(); =20 -=09=09if (loaned_pages_target > loaned_pages) { -=09=09=09if (cmm_alloc_pages(loaned_pages_target - loaned_pages)) -=09=09=09=09loaned_pages_target =3D loaned_pages; -=09=09} else if (loaned_pages_target < loaned_pages) -=09=09=09cmm_free_pages(loaned_pages - loaned_pages_target); +=09=09__loaned_pages =3D atomic_long_read(&loaned_pages); +=09=09if (loaned_pages_target > __loaned_pages) { +=09=09=09if (cmm_alloc_pages(loaned_pages_target - __loaned_pages)) +=09=09=09=09loaned_pages_target =3D __loaned_pages; +=09=09} else if (loaned_pages_target < __loaned_pages) +=09=09=09cmm_free_pages(__loaned_pages - loaned_pages_target); =09} =09return 0; } @@ -330,7 +333,7 @@ static int cmm_thread(void *dummy) =09}=09=09=09=09=09=09=09\ =09static DEVICE_ATTR(name, 0444, show_##name, NULL) =20 -CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages)); +CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(atomic_long_read(&loaned_pages))); CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target)); =20 static ssize_t show_oom_pages(struct device *dev, @@ -433,7 +436,7 @@ static int cmm_reboot_notifier(struct notifier_block *n= b, =09=09if (cmm_thread_ptr) =09=09=09kthread_stop(cmm_thread_ptr); =09=09cmm_thread_ptr =3D NULL; -=09=09cmm_free_pages(loaned_pages); +=09=09cmm_free_pages(atomic_long_read(&loaned_pages)); =09} =09return NOTIFY_DONE; } @@ -540,7 +543,7 @@ static void cmm_exit(void) =09unregister_oom_notifier(&cmm_oom_nb); =09unregister_reboot_notifier(&cmm_reboot_nb); =09unregister_memory_notifier(&cmm_mem_nb); -=09cmm_free_pages(loaned_pages); +=09cmm_free_pages(atomic_long_read(&loaned_pages)); =09cmm_unregister_sysfs(&cmm_dev); } =20 @@ -561,7 +564,7 @@ static int cmm_set_disable(const char *val, const struc= t kernel_param *kp) =09=09if (cmm_thread_ptr) =09=09=09kthread_stop(cmm_thread_ptr); =09=09cmm_thread_ptr =3D NULL; -=09=09cmm_free_pages(loaned_pages); +=09=09cmm_free_pages(atomic_long_read(&loaned_pages)); =09} else if (!disable && cmm_disabled) { =09=09cmm_thread_ptr =3D kthread_run(cmm_thread, NULL, "cmmthread"); =09=09if (IS_ERR(cmm_thread_ptr)) --=20 2.21.0