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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7755EC43334 for ; Fri, 15 Jul 2022 15:43:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235862AbiGOPnV (ORCPT ); Fri, 15 Jul 2022 11:43:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235507AbiGOPml (ORCPT ); Fri, 15 Jul 2022 11:42:41 -0400 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA1645D59F for ; Fri, 15 Jul 2022 08:42:34 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0VJPnC8L_1657899746; Received: from e18g06460.et15sqa.tbsite.net(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VJPnC8L_1657899746) by smtp.aliyun-inc.com; Fri, 15 Jul 2022 23:42:27 +0800 From: Gao Xiang To: linux-erofs@lists.ozlabs.org, Chao Yu Cc: LKML , Gao Xiang Subject: [PATCH v2 13/16] erofs: try to leave (de)compressed_pages on stack if possible Date: Fri, 15 Jul 2022 23:42:00 +0800 Message-Id: <20220715154203.48093-14-hsiangkao@linux.alibaba.com> X-Mailer: git-send-email 2.24.4 In-Reply-To: <20220715154203.48093-1-hsiangkao@linux.alibaba.com> References: <20220715154203.48093-1-hsiangkao@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For the most cases, small pclusters can be decompressed with page arrays on stack. Try to leave both (de)compressed_pages on stack if possible as before. Signed-off-by: Gao Xiang --- fs/erofs/zdata.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 1cf377ed1452..d93ba0adcf9e 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -858,6 +858,7 @@ struct z_erofs_decompress_backend { struct page **compressed_pages; struct page **pagepool; + unsigned int onstack_used; }; static int z_erofs_parse_out_bvecs(struct z_erofs_decompress_backend *be) @@ -904,14 +905,9 @@ static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be, { struct z_erofs_pcluster *pcl = be->pcl; unsigned int pclusterpages = z_erofs_pclusterpages(pcl); - struct page **compressed_pages; int i, err = 0; - /* XXX: will have a better approach in the following commits */ - compressed_pages = kmalloc_array(pclusterpages, sizeof(struct page *), - GFP_KERNEL | __GFP_NOFAIL); *overlapped = false; - for (i = 0; i < pclusterpages; ++i) { struct z_erofs_bvec *bvec = &pcl->compressed_bvecs[i]; struct page *page = bvec->page; @@ -922,7 +918,7 @@ static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be, DBG_BUGON(1); continue; } - compressed_pages[i] = page; + be->compressed_pages[i] = page; if (z_erofs_is_inline_pcluster(pcl)) { if (!PageUptodate(page)) @@ -953,11 +949,8 @@ static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be, } } - if (err) { - kfree(compressed_pages); + if (err) return err; - } - be->compressed_pages = compressed_pages; return 0; } @@ -976,15 +969,28 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be, mutex_lock(&pcl->lock); nr_pages = pcl->nr_pages; + /* allocate (de)compressed page arrays if cannot be kept on stack */ + be->decompressed_pages = NULL; + be->compressed_pages = NULL; + be->onstack_used = 0; if (nr_pages <= Z_EROFS_ONSTACK_PAGES) { be->decompressed_pages = be->onstack_pages; + be->onstack_used = nr_pages; memset(be->decompressed_pages, 0, sizeof(struct page *) * nr_pages); - } else { + } + + if (pclusterpages + be->onstack_used <= Z_EROFS_ONSTACK_PAGES) + be->compressed_pages = be->onstack_pages + be->onstack_used; + + if (!be->decompressed_pages) be->decompressed_pages = kvcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL | __GFP_NOFAIL); - } + if (!be->compressed_pages) + be->compressed_pages = + kvcalloc(pclusterpages, sizeof(struct page *), + GFP_KERNEL | __GFP_NOFAIL); err2 = z_erofs_parse_out_bvecs(be); if (err2) @@ -1041,7 +1047,9 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be, WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); } } - kfree(be->compressed_pages); + if (be->compressed_pages < be->onstack_pages || + be->compressed_pages >= be->onstack_pages + Z_EROFS_ONSTACK_PAGES) + kvfree(be->compressed_pages); for (i = 0; i < nr_pages; ++i) { page = be->decompressed_pages[i]; -- 2.24.4