From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D32137157 for ; Tue, 13 Feb 2024 11:14:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707822848; cv=none; b=h+ajqUy0iEvzgNfFPZTDnh0dttYLJWbTNRR/4TmWBPez7HMy6kL+SuILFhudSdMGbQQ3vQO/6dqV4ik6AfjTE0BG/jUXQDykp2eJfZwWRqtag2HXo2XUdVj5PK314qXvY45FPypORpaH1VDZUWGuG0MIXtpxWQOkpWcWUoLuD84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707822848; c=relaxed/simple; bh=Pp4c82WxUcYPpLVo+HDh/cBM14HTiOMmYLsLLHJOEgE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=sy7C/M5hAEW7BNSuuCvADwDExniiqkIw1LNJcCp51qGOu6TYUVcfZ731l46Eh6K6kQItXiXYPlL58aCwjC8v0ifLL+u5evprpcK/s133DlYI5JGbmyh1vwc73y8OrK3X/OqSb3apZ0BqMdKpe7MZycKDq/TPsbpsPh7BPL8nQIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ZPI670aF; arc=none smtp.client-ip=91.218.175.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ZPI670aF" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1707822844; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3HNW+BWPQLZLSA9Wsdie7SM7+Z9Dq4YTo1Xwh/Ut0N0=; b=ZPI670aF7l5C2zzwKvIqmcFcaMTzMQXxlEsYJ10wrPsJHywJ67w1IkzFeJ/ZcwvX7xafSW yXfXogGU+DMHmth/vH46c00MhNvLCEPEGGBlvc7AN/c1ZL/3/ha2zPzbUzKY1h4fRsHcas pZeE8v64mDTmFPEItAV5JpOFcIUSt4s= From: Gang Li To: Andrew Morton , Steffen Klassert , Daniel Jordan , Jane Chu , "Paul E . McKenney" , Muchun Song , Gang Li , Randy Dunlap , kernel test robot , Gang Li Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v1 1/2] padata: downgrade padata_do_multithreaded to serial execution for non-SMP Date: Tue, 13 Feb 2024 19:13:46 +0800 Message-Id: <20240213111347.3189206-2-gang.li@linux.dev> In-Reply-To: <20240213111347.3189206-1-gang.li@linux.dev> References: <20240213111347.3189206-1-gang.li@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Randy Dunlap and kernel test robot reported a warning: ``` WARNING: unmet direct dependencies detected for PADATA Depends on [n]: SMP [=n] Selected by [y]: - HUGETLBFS [=y] && (X86 [=y] || SPARC64 || ARCH_SUPPORTS_HUGETLBFS [=n] || BROKEN [=n]) && (SYSFS [=y] || SYSCTL [=n]) ``` hugetlb parallelization depends on PADATA, and PADATA depends on SMP. PADATA consists of two distinct functionality: One part is padata_do_multithreaded which disregards order and simply divides tasks into several groups for parallel execution. Hugetlb init parallelization depends on padata_do_multithreaded. The other part is composed of a set of APIs that, while handling data in an out-of-order parallel manner, can eventually return the data with ordered sequence. Currently Only `crypto/pcrypt.c` use them. All users of PADATA of non-SMP case currently only use padata_do_multithreaded. It is easy to implement a serial one in include/linux/padata.h. And it is not necessary to implement another functionality unless the only user of crypto/pcrypt.c does not depend on SMP in the future. Fixes: a2cefb08be66 ("hugetlb: have CONFIG_HUGETLBFS select CONFIG_PADATA") Reported-by: Randy Dunlap Closes: https://lore.kernel.org/lkml/ec5dc528-2c3c-4444-9e88-d2c48395b433@infradead.org/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202402020454.6EPkP1hi-lkp@intel.com/ Signed-off-by: Gang Li --- fs/Kconfig | 2 +- include/linux/padata.h | 13 +++++++++---- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/Kconfig b/fs/Kconfig index 4a51331f172e5..7963939592d70 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -261,7 +261,7 @@ menuconfig HUGETLBFS depends on X86 || SPARC64 || ARCH_SUPPORTS_HUGETLBFS || BROKEN depends on (SYSFS || SYSCTL) select MEMFD_CREATE - select PADATA + select PADATA if SMP help hugetlbfs is a filesystem backing for HugeTLB pages, based on ramfs. For architectures that support it, say Y here and read diff --git a/include/linux/padata.h b/include/linux/padata.h index 8f418711351bc..7b84eb7d73e7f 100644 --- a/include/linux/padata.h +++ b/include/linux/padata.h @@ -180,10 +180,6 @@ struct padata_instance { #ifdef CONFIG_PADATA extern void __init padata_init(void); -#else -static inline void __init padata_init(void) {} -#endif - extern struct padata_instance *padata_alloc(const char *name); extern void padata_free(struct padata_instance *pinst); extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst); @@ -194,4 +190,13 @@ extern void padata_do_serial(struct padata_priv *padata); extern void __init padata_do_multithreaded(struct padata_mt_job *job); extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, cpumask_var_t cpumask); +#else +static inline void __init padata_init(void) {} +static inline void __init padata_do_multithreaded(struct padata_mt_job *job) +{ + if (job->size) + job->thread_fn(job->start, job->start + job->size, job->fn_arg); +} +#endif + #endif -- 2.20.1