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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 718E5C282CE for ; Tue, 4 Jun 2019 22:43:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3664D206BB for ; Tue, 4 Jun 2019 22:43:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559688209; bh=McnH01l012LgpITPnazCqRJYDfp8SFNlTpLeOyd0rDk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=vgyDyNgaY7lEvqChEw9FhmQCtswinMvCCucHKyJL5J4SI7dRVrqUF3/juDaBmC/QV DgEa5g7FvsMYQ0/JE2U54NTKpf7p2Z2BsCpHyRtLfX9lRTyPHbYmgMb3GVMwAQpoNi B3mLoWqu/VLAgjsWoIUR4M+UidBHJ0YREcT5siCw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726521AbfFDWn2 (ORCPT ); Tue, 4 Jun 2019 18:43:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:44768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726179AbfFDWn2 (ORCPT ); Tue, 4 Jun 2019 18:43:28 -0400 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 92F10206B8; Tue, 4 Jun 2019 22:43:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559688207; bh=McnH01l012LgpITPnazCqRJYDfp8SFNlTpLeOyd0rDk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=iMpvIC1KpLUBc26GINzifM0DVnm8whlDtaLjgjFzkGsUuxLi4URKQ7Kz86LO1axJb ROYDLOE5iJKCfO3e/mDuVFq36lJWgmDFCC1r7h0nwP2pLpHpITo/a8kmnu+8Xlf8E5 EsXgRa+o7Hse3+A4mDjXy7HiDjwS37jUW3oVHF+8= Date: Tue, 4 Jun 2019 15:43:26 -0700 From: Andrew Morton To: Maninder Singh Cc: herbert@gondor.apana.org.au, davem@davemloft.net, keescook@chromium.org, gustavo@embeddedor.com, joe@perches.com, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, a.sahrawat@samsung.com, pankaj.m@samsung.com, v.narang@samsung.com, Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org Subject: Re: [PATCH 1/4] zstd: pass pointer rathen than structure to functions Message-Id: <20190604154326.8868a10f896c148a0ce804d1@linux-foundation.org> In-Reply-To: <1559552526-4317-2-git-send-email-maninder1.s@samsung.com> References: <1559552526-4317-1-git-send-email-maninder1.s@samsung.com> <1559552526-4317-2-git-send-email-maninder1.s@samsung.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 3 Jun 2019 14:32:03 +0530 Maninder Singh wrote: > currently params structure is passed in all functions, which increases > stack usage in all the function and lead to stack overflow on target like > ARM with kernel stack size of 8 KB so better to pass pointer. > > Checked for ARM: > > Original Patched > Call FLow Size: 1264 1040 > .... > (HUF_sort) -> 296 > (HUF_buildCTable_wksp) -> 144 > (HUF_compress4X_repeat) -> 88 > (ZSTD_compressBlock_internal) -> 200 > (ZSTD_compressContinue_internal)-> 136 -> 88 > (ZSTD_compressCCtx) -> 192 -> 64 > (zstd_compress) -> 144 -> 96 > (crypto_compress) -> 32 > (zcomp_compress) -> 32 > .... > > Signed-off-by: Maninder Singh > Signed-off-by: Vaneet Narang > You missed btrfs. This needs review, please - particularly the kernel-wide static ZSTD_parameters in zstd_get_btrfs_parameters(). The base patch is here: http://lkml.kernel.org/r/1559552526-4317-2-git-send-email-maninder1.s@samsung.com --- a/fs/btrfs/zstd.c~zstd-pass-pointer-rathen-than-structure-to-functions-fix +++ a/fs/btrfs/zstd.c @@ -27,15 +27,17 @@ /* 307s to avoid pathologically clashing with transaction commit */ #define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ) -static ZSTD_parameters zstd_get_btrfs_parameters(unsigned int level, +static ZSTD_parameters *zstd_get_btrfs_parameters(unsigned int level, size_t src_len) { - ZSTD_parameters params = ZSTD_getParams(level, src_len, 0); + static ZSTD_parameters params; + + params = ZSTD_getParams(level, src_len, 0); if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG) params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG; WARN_ON(src_len > ZSTD_BTRFS_MAX_INPUT); - return params; + return ¶ms; } struct workspace { @@ -155,11 +157,12 @@ static void zstd_calc_ws_mem_sizes(void) unsigned int level; for (level = 1; level <= ZSTD_BTRFS_MAX_LEVEL; level++) { - ZSTD_parameters params = - zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); - size_t level_size = - max_t(size_t, - ZSTD_CStreamWorkspaceBound(params.cParams), + ZSTD_parameters *params; + size_t level_size; + + params = zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); + level_size = max_t(size_t, + ZSTD_CStreamWorkspaceBound(params->cParams), ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT)); max_size = max_t(size_t, max_size, level_size); @@ -385,8 +388,9 @@ static int zstd_compress_pages(struct li unsigned long len = *total_out; const unsigned long nr_dest_pages = *out_pages; unsigned long max_out = nr_dest_pages * PAGE_SIZE; - ZSTD_parameters params = zstd_get_btrfs_parameters(workspace->req_level, - len); + ZSTD_parameters *params; + + params = zstd_get_btrfs_parameters(workspace->req_level, len); *out_pages = 0; *total_out = 0; _