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 Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3B5CAC77B6C for ; Thu, 13 Apr 2023 09:21:30 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 1086B3CC4CF for ; Thu, 13 Apr 2023 11:21:28 +0200 (CEST) Received: from in-6.smtp.seeweb.it (in-6.smtp.seeweb.it [IPv6:2001:4b78:1:20::6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 0D3E53CC3BC for ; Thu, 13 Apr 2023 11:21:18 +0200 (CEST) Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-6.smtp.seeweb.it (Postfix) with ESMTPS id 691481400B7F for ; Thu, 13 Apr 2023 11:21:16 +0200 (CEST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id E802A1FD63; Thu, 13 Apr 2023 09:21:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1681377675; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=utbtt6f/E49AIcIivOYeKISdG38SvlMYnvPuV/lEidM=; b=U80PLEhOCpJw6QcYHLKaYz+7p4pZEShx0+TKIxj+bAY8HO54+//+ieA2rghET5okV/lGyB IGnYKyz3uzlJWja90hWnstvHNFVYeup47J58gD21S+NrsZp++UAGI3seIv/xARUwmV3y6G l44JF4N+4372VKJdURyxOVE7pW0smBM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1681377675; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=utbtt6f/E49AIcIivOYeKISdG38SvlMYnvPuV/lEidM=; b=ngqZ9NK2Q8n51aT9mbG1UeDBFh3RXWVa3D+j+nxDq4RXf42FplnpkzGLwUjvFZ/H7ICTtr lAgEXFkOjdOpmmCA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C3A6713421; Thu, 13 Apr 2023 09:21:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id BkSTLovJN2SxLQAAMHmgww (envelope-from ); Thu, 13 Apr 2023 09:21:15 +0000 Date: Thu, 13 Apr 2023 11:22:21 +0200 From: Cyril Hrubis To: Tarun Sahu Message-ID: References: <20230413090753.883953-1-tsahu@linux.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230413090753.883953-1-tsahu@linux.ibm.com> X-Virus-Scanned: clamav-milter 0.102.4 at in-6.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH] Hugetlb: Test to detect bug with freeing gigantic hugetlb pages X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: piyushs@linux.ibm.com, aneesh.kumar@linux.ibm.com, jaypatel@linux.ibm.com, geetika@linux.ibm.com, rpalethorpe@suse.com, ltp@lists.linux.it Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hi! > +/*\ > + * [Description] > + * > + * Before kernel version 5.10-rc7, there was a bug that resulted in a "Bad Page > + * State" error when freeing gigantic hugepages. This happened because the > + * struct page entry compound_nr, which overlapped with page->mapping in the > + * first tail page, was not cleared, causing the error. To ensure that this > + * issue does not reoccur as struct page keeps changing and some fields are > + * managed by folio, this test checks that freeing gigantic hugepages does not > + * produce the above-mentioned error. > + */ > + > +#define _GNU_SOURCE > +#include > + > +#include > + > +#include "hugetlb.h" > + > +#define PATH_GIGANTIC_HUGEPAGE "/sys/kernel/mm/hugepages" > +#define GIGANTIC_MIN_ORDER 10 > + > +static int org_g_hpages; > +static char g_hpage_path[4096]; > + > +static void run_test(void) > +{ > + SAFE_FILE_PRINTF(g_hpage_path, "%d", 1); I suppose this may still fail if there is not enough memory or the memory is fragmented, right? I suppose that SAFE_FILE_PRINTF() will cause TBROK here, right? Maybe we should just use FILE_PRINTF() and ignore the errors. > + SAFE_FILE_PRINTF(g_hpage_path, "%d", 0); > + if (tst_taint_check()) > + tst_res(TFAIL, "Freeing Gigantic pages resulted in Bad Page State bug."); > + else > + tst_res(TPASS, "Successfully freed the gigantic hugepages"); > +} > + > +static void setup(void) > +{ > + DIR *dir; > + struct dirent *ent; > + char *hpage_size_str; > + unsigned long hpage_size; > + > + dir = SAFE_OPENDIR(PATH_GIGANTIC_HUGEPAGE); > + while ((ent = SAFE_READDIR(dir)) != NULL) { ^ The != NULL is redundant > + if (strstr(ent->d_name, "hugepages-") != NULL) { > + hpage_size_str = ent->d_name + strlen("hugepages-"); > + hpage_size = atoi(hpage_size_str) * 1024; Can we just do: if ((sscanf(ent->d_name, "hugepages-%lu", &hpage_size) == 1) && is_hugetlb_gigantic(hpage_size * 1024)) { sprintf(...); } > + if (is_hugetlb_gigantic(hpage_size)) { > + sprintf(g_hpage_path, "%s/%s/%s", > + PATH_GIGANTIC_HUGEPAGE, ent->d_name, "nr_hugepages"); > + break; > + } > + } > + } > + SAFE_CLOSEDIR(dir); We should handle the case that there were no large hugepages found on the system. On one of my machines: # ls /sys/kernel/mm/hugepages/ hugepages-2048kB # I suppose: if (!g_hpage_path[0]) tst_brk(TCONF, "Gigantic hugepages not supported"); > + SAFE_FILE_LINES_SCANF(g_hpage_path, "%d", &org_g_hpages); > +} > + > +static void cleanup(void) > +{ > + SAFE_FILE_PRINTF(g_hpage_path, "%d", org_g_hpages); > +} > + > +static struct tst_test test = { > + .tags = (struct tst_tag[]) { > + {"linux-git", "ba9c1201beaa"}, > + {"linux-git", "7118fc2906e9"}, > + {} > + }, > + .needs_root = 1, > + .setup = setup, > + .cleanup = cleanup, > + .test_all = run_test, > + .taint_check = TST_TAINT_B, > +}; > diff --git a/testcases/kernel/mem/hugetlb/lib/hugetlb.h b/testcases/kernel/mem/hugetlb/lib/hugetlb.h > index 241dab708..34fe08c24 100644 > --- a/testcases/kernel/mem/hugetlb/lib/hugetlb.h > +++ b/testcases/kernel/mem/hugetlb/lib/hugetlb.h > @@ -39,6 +39,12 @@ > # endif > #endif > > +/* Check if hugetlb page is gigantic */ > +static inline int is_hugetlb_gigantic(unsigned long hpage_size) > +{ > + return (hpage_size / getpagesize()) >> 11; > +} > + > /* > * to get the lower nine permission bits > * from shmid_ds.ipc_perm.mode > -- > 2.31.1 > -- Cyril Hrubis chrubis@suse.cz -- Mailing list info: https://lists.linux.it/listinfo/ltp