From patchwork Tue Apr 2 20:41:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Jordan X-Patchwork-Id: 1075005 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 44Yjdd3gZnz9sPb for ; Wed, 3 Apr 2019 08:53:41 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=oracle.com header.i=@oracle.com header.b="xBffgtoj"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44Yjdd2P4CzDqRN for ; 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Tue, 02 Apr 2019 20:42:25 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x32KgPpX030145; Tue, 2 Apr 2019 20:42:25 GMT Received: from localhost.localdomain (/73.60.114.248) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 02 Apr 2019 13:42:25 -0700 From: Daniel Jordan To: akpm@linux-foundation.org Subject: [PATCH 6/6] kvm/book3s: drop mmap_sem now that locked_vm is atomic Date: Tue, 2 Apr 2019 16:41:58 -0400 Message-Id: <20190402204158.27582-7-daniel.m.jordan@oracle.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190402204158.27582-1-daniel.m.jordan@oracle.com> References: <20190402204158.27582-1-daniel.m.jordan@oracle.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9215 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=29 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904020138 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9215 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=29 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904020138 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Davidlohr Bueso , Alexey Kardashevskiy , linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, daniel.m.jordan@oracle.com, linux-mm@kvack.org, Christoph Lameter , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" With locked_vm now an atomic, there is no need to take mmap_sem as writer. Delete and refactor accordingly. Signed-off-by: Daniel Jordan Cc: Alexey Kardashevskiy Cc: Andrew Morton Cc: Benjamin Herrenschmidt Cc: Christoph Lameter Cc: Davidlohr Bueso Cc: Michael Ellerman Cc: Paul Mackerras Cc: Cc: Cc: Cc: --- arch/powerpc/kvm/book3s_64_vio.c | 34 +++++++++++--------------------- 1 file changed, 12 insertions(+), 22 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index e7fdb6d10eeb..8e034c3a5d25 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -56,7 +56,7 @@ static unsigned long kvmppc_stt_pages(unsigned long tce_pages) return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE; } -static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc) +static long kvmppc_account_memlimit(unsigned long pages, bool inc) { long ret = 0; s64 locked_vm; @@ -64,33 +64,23 @@ static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc) if (!current || !current->mm) return ret; /* process exited */ - down_write(¤t->mm->mmap_sem); - - locked_vm = atomic64_read(¤t->mm->locked_vm); if (inc) { - unsigned long locked, lock_limit; + unsigned long lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - locked = locked_vm + stt_pages; - lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) + locked_vm = atomic64_add_return(pages, ¤t->mm->locked_vm); + if (locked_vm > lock_limit && !capable(CAP_IPC_LOCK)) { ret = -ENOMEM; - else - atomic64_add(stt_pages, ¤t->mm->locked_vm); + atomic64_sub(pages, ¤t->mm->locked_vm); + } } else { - if (WARN_ON_ONCE(stt_pages > locked_vm)) - stt_pages = locked_vm; - - atomic64_sub(stt_pages, ¤t->mm->locked_vm); + locked_vm = atomic64_sub_return(pages, ¤t->mm->locked_vm); + WARN_ON_ONCE(locked_vm < 0); } - pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid, - inc ? '+' : '-', - stt_pages << PAGE_SHIFT, - atomic64_read(¤t->mm->locked_vm) << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK), - ret ? " - exceeded" : ""); - - up_write(¤t->mm->mmap_sem); + pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%lu %lld/%lu%s\n", current->pid, + inc ? '+' : '-', pages << PAGE_SHIFT, + locked_vm << PAGE_SHIFT, + rlimit(RLIMIT_MEMLOCK), ret ? " - exceeded" : ""); return ret; }