From patchwork Fri Aug 7 06:18:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11704741 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 7E51214B7 for ; Fri, 7 Aug 2020 06:18:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4FD7122D07 for ; Fri, 7 Aug 2020 06:18:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="csOCmnfY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4FD7122D07 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 13CAC8D0021; Fri, 7 Aug 2020 02:18:51 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 0C54D8D000F; Fri, 7 Aug 2020 02:18:51 -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 001AE8D0021; Fri, 7 Aug 2020 02:18:50 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0025.hostedemail.com [216.40.44.25]) by kanga.kvack.org (Postfix) with ESMTP id DC7ED8D000F for ; Fri, 7 Aug 2020 02:18:50 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id A47F93641 for ; Fri, 7 Aug 2020 06:18:50 +0000 (UTC) X-FDA: 77122769220.18.unit03_46016a526fbe Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id 823E3100EC676 for ; Fri, 7 Aug 2020 06:18:50 +0000 (UTC) X-Spam-Summary: 1,0,0,93f63a936ffa75f0,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:69:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2198:2199:2393:2525:2559:2563:2682:2685:2859:2895:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3870:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6119:6261:6653:6737:7576:7903:8599:8784:9025:9545:9592:10004:10913:11026:11473:11658:11914:12043:12048:12296:12297:12438:12517:12519:12555:12679:12783:12986:13069:13161:13229:13311:13357:13846:14181:14384:14721:14849:21080:21450:21451:21627:21795:21939:21990:30051:30054:30064:30070,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-62.2.0.100 64.100.201.201;04yfw893eo1si773y7zrdr9bqb67woc7rq31an3rj9rak6z3zyojm8u5muhnfzo.rtwpih7kbhd5c38ujba5qq4s6tfbj7xi4j6xwnfmn783zscdhzzth8nz1sct1xi.s-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0 .5,0.5,0 X-HE-Tag: unit03_46016a526fbe X-Filterd-Recvd-Size: 3360 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Fri, 7 Aug 2020 06:18:50 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1620922CB3; Fri, 7 Aug 2020 06:18:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781129; bh=MfO/fZsVOJp9DxsWMlg6hC+zRDpAKLgREa7mDK4tp+Q=; h=Date:From:To:Subject:In-Reply-To:From; b=csOCmnfY8MqClNgY5H17Q5Lzk/IQ6RD/ss+Jk369U4tzCGN7NYU3NmArV2+f2bGPD NJhwYsA8hHiwrDOBgfaR67LiDzYoIcDXMXG8naHzHzs0p8QRQcaPPjqLL7VcKWey0H uLVzS0J+S9nb9IRJ5TWwTkFoQkLJmVWTlfWuXnrQ= Date: Thu, 06 Aug 2020 23:18:48 -0700 From: Andrew Morton To: akpm@linux-foundation.org, cl@linux.com, guro@fb.com, iamjoonsoo.kim@lge.com, jannh@google.com, keescook@chromium.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, penberg@kernel.org, rientjes@google.com, torvalds@linux-foundation.org, vbabka@suse.cz, vjitta@codeaurora.org Subject: [patch 032/163] mm, slub: make reclaim_account attribute read-only Message-ID: <20200807061848.vF8DVDKGT%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 823E3100EC676 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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: From: Vlastimil Babka Subject: mm, slub: make reclaim_account attribute read-only 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. Link: http://lkml.kernel.org/r/20200610163135.17364-6-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: Kees Cook Acked-by: Roman Gushchin Cc: Christoph Lameter Cc: Jann Horn Cc: Vijayanand Jitta Cc: David Rientjes Cc: Joonsoo Kim Cc: Pekka Enberg Signed-off-by: Andrew Morton --- mm/slub.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) --- a/mm/slub.c~mm-slub-make-reclaim_account-attribute-read-only +++ a/mm/slub.c @@ -5207,16 +5207,7 @@ static ssize_t reclaim_account_show(stru { 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) {