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 973D3ECAAD1 for ; Sat, 27 Aug 2022 03:22:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233538AbiH0DWH (ORCPT ); Fri, 26 Aug 2022 23:22:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233267AbiH0DWG (ORCPT ); Fri, 26 Aug 2022 23:22:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF9C5BC81D for ; Fri, 26 Aug 2022 20:22:05 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7BC3661DCB for ; Sat, 27 Aug 2022 03:22:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0B12C433D6; Sat, 27 Aug 2022 03:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1661570524; bh=ZiMqqNBzmHz4Lpr0jXbch5kBsBn1+OmYRSUekYFKZBM=; h=Date:To:From:Subject:From; b=d/wsFp0b6fQnJvzniuZH6pI7sD1cggPsXLe3/SInFTYIe0UaSzQ2XXD9+X1Ig71YR V9dLrhm68HDiGaU7l1qwBWRFV5ZprlzEebfPdJMNWEXnLzrVfO1s821IgyrS+mdsFi nY5jOmGMIBnk6yoO6FUoqLzZj0Xr4Tbf/3s8uJ5c= Date: Fri, 26 Aug 2022 20:22:04 -0700 To: mm-commits@vger.kernel.org, senozhatsky@chromium.org, ngupta@vflare.org, minchan@kernel.org, DDRokosov@sberdevices.ru, ddrokosov@sberdevices.ru, avromanov@sberdevices.ru, akpm@linux-foundation.org From: Andrew Morton Subject: + zram-dont-retry-compress-incompressible-page.patch added to mm-unstable branch Message-Id: <20220827032204.C0B12C433D6@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: zram: don't retry compress incompressible page has been added to the -mm mm-unstable branch. Its filename is zram-dont-retry-compress-incompressible-page.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-dont-retry-compress-incompressible-page.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Alexey Romanov Subject: zram: don't retry compress incompressible page Date: Wed, 24 Aug 2022 14:31:17 +0300 It doesn't make sense for us to retry to compress an uncompressible page (comp_len == PAGE_SIZE) in zsmalloc slowpath, because we will be storing it uncompressed anyway. We can avoid wasting time on another compression attempt. It is enough to take lock (zcomp_stream_get) and execute the code below. Link: https://lkml.kernel.org/r/20220824113117.78849-1-avromanov@sberdevices.ru Signed-off-by: Alexey Romanov Signed-off-by: Dmitry Rokosov Reviewed-by: Sergey Senozhatsky Cc: Alexey Romanov Cc: Dmitry Rokosov Cc: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/drivers/block/zram/zram_drv.c~zram-dont-retry-compress-incompressible-page +++ a/drivers/block/zram/zram_drv.c @@ -1410,9 +1410,19 @@ compress_again: handle = zs_malloc(zram->mem_pool, comp_len, GFP_NOIO | __GFP_HIGHMEM | __GFP_MOVABLE); - if (!IS_ERR((void *)handle)) + if (IS_ERR((void *)handle)) + return PTR_ERR((void *)handle); + + if (comp_len != PAGE_SIZE) goto compress_again; - return PTR_ERR((void *)handle); + /* + * If the page is not compressible, you need to acquire the lock and + * execute the code below. The zcomp_stream_get() call is needed to + * disable the cpu hotplug and grab the zstrm buffer back. + * It is necessary that the dereferencing of the zstrm variable below + * occurs correctly. + */ + zstrm = zcomp_stream_get(zram->comp); } alloced_pages = zs_get_total_pages(zram->mem_pool); _ Patches currently in -mm which might be from avromanov@sberdevices.ru are zsmalloc-zs_object_copy-add-clarifying-comment.patch zsmalloc-remove-unnecessary-size_class-null-check.patch zsmalloc-zs_object_copy-replace-email-link-to-doc.patch zram-dont-retry-compress-incompressible-page.patch