From patchwork Wed Jun 10 16:31:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vlastimil Babka X-Patchwork-Id: 11598295 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 97C811391 for ; Wed, 10 Jun 2020 16:32:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6F5232070B for ; Wed, 10 Jun 2020 16:32:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F5232070B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C0D26B0073; Wed, 10 Jun 2020 12:31:59 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 04B8C6B0075; Wed, 10 Jun 2020 12:31:58 -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 E58836B0078; Wed, 10 Jun 2020 12:31:58 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0216.hostedemail.com [216.40.44.216]) by kanga.kvack.org (Postfix) with ESMTP id C7CFF6B0073 for ; Wed, 10 Jun 2020 12:31:58 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8AA6945456 for ; Wed, 10 Jun 2020 16:31:58 +0000 (UTC) X-FDA: 76913843916.01.leaf37_230db9326dcc Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin01.hostedemail.com (Postfix) with ESMTP id 2B07918027472 for ; Wed, 10 Jun 2020 16:31:55 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,vbabka@suse.cz,,RULES_HIT:30051:30054:30064:30070,0,RBL:195.135.220.15:@suse.cz:.lbl8.mailshell.net-62.2.6.2 64.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:23,LUA_SUMMARY:none X-HE-Tag: leaf37_230db9326dcc X-Filterd-Recvd-Size: 2767 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Wed, 10 Jun 2020 16:31:54 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 0B2CCAF2C; Wed, 10 Jun 2020 16:31:55 +0000 (UTC) From: Vlastimil Babka To: Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com, vinmenon@codeaurora.org, Kees Cook , Matthew Garrett , Roman Gushchin , Vlastimil Babka , Jann Horn , Vijayanand Jitta Subject: [PATCH 5/9] mm, slub: make reclaim_account attribute read-only Date: Wed, 10 Jun 2020 18:31:31 +0200 Message-Id: <20200610163135.17364-6-vbabka@suse.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200610163135.17364-1-vbabka@suse.cz> References: <20200610163135.17364-1-vbabka@suse.cz> MIME-Version: 1.0 X-Rspamd-Queue-Id: 2B07918027472 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: The attribute reflects the SLAB_RECLAIM_ACCOUNT cache flag. It's not clear why this attribute was writable in the first place, as it's tied to how the cache is used by its creator, it's not a user tunable. Furthermore: - it affects slab merging, but that's not being checked while toggled - if affects whether __GFP_RECLAIMABLE flag is used to allocate page, but the runtime toggle doesn't update allocflags - it affects cache_vmstat_idx() so runtime toggling might lead to incosistency of NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE Thus make it read-only. Signed-off-by: Vlastimil Babka Reviewed-by: Kees Cook Acked-by: Roman Gushchin --- mm/slub.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 0108829838e7..8dd2925448ae 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5223,16 +5223,7 @@ static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) { return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); } - -static ssize_t reclaim_account_store(struct kmem_cache *s, - const char *buf, size_t length) -{ - s->flags &= ~SLAB_RECLAIM_ACCOUNT; - if (buf[0] == '1') - s->flags |= SLAB_RECLAIM_ACCOUNT; - return length; -} -SLAB_ATTR(reclaim_account); +SLAB_ATTR_RO(reclaim_account); static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) {