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 C7E55ECAAD5 for ; Sat, 27 Aug 2022 22:28:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229455AbiH0W27 (ORCPT ); Sat, 27 Aug 2022 18:28:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230083AbiH0W26 (ORCPT ); Sat, 27 Aug 2022 18:28:58 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 422F243E6B for ; Sat, 27 Aug 2022 15:28:56 -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 ams.source.kernel.org (Postfix) with ESMTPS id B1B34B807E8 for ; Sat, 27 Aug 2022 22:28:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B5CFC433D6; Sat, 27 Aug 2022 22:28:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1661639334; bh=yHDsIDql+tXNmtwt9+54Jh4CWI/KoLwWGDDxP+coXnc=; h=Date:To:From:Subject:From; b=f1GCD+QT2WkLyrGd/bwWY4W9h4p0YhOZ9jXeNF9L9gSjmWvFEaztXPsYkUKAzI1SF seSn3LrrKM15wNPVmjqx/LJ1O8Tkix0bFXDai+r3INqUisDXE+kHgKYiy+NY7ehoTM 6lg010aeiIT9gfsZXXbUlA1wv6b349P7jtccNS68= Date: Sat, 27 Aug 2022 15:28:53 -0700 To: mm-commits@vger.kernel.org, viro@zeniv.linux.org.uk, trond.myklebust@hammerspace.com, miklos@szeredi.hu, logang@deltatee.com, jack@suse.cz, hch@infradead.org, djwong@kernel.org, axboe@kernel.dk, anna@kernel.org, jhubbard@nvidia.com, akpm@linux-foundation.org From: Andrew Morton Subject: + block-add-dio_w_-wrappers-for-pin-unpin-user-pages.patch added to mm-unstable branch Message-Id: <20220827222854.6B5CFC433D6@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: block: add dio_w_*() wrappers for pin, unpin user pages has been added to the -mm mm-unstable branch. Its filename is block-add-dio_w_-wrappers-for-pin-unpin-user-pages.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/block-add-dio_w_-wrappers-for-pin-unpin-user-pages.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: John Hubbard Subject: block: add dio_w_*() wrappers for pin, unpin user pages Date: Sat, 27 Aug 2022 01:36:03 -0700 Background: The Direct IO part of the block infrastructure is being changed to use pin_user_page*() and unpin_user_page*() calls, in place of a mix of get_user_pages_fast(), get_page(), and put_page(). These have to be changed over all at the same time, for block, bio, and all filesystems. However, most filesystems can be changed via iomap and core filesystem routines, so let's get that in place, and then continue on with converting the remaining filesystems (9P, CIFS) and anything else that feeds pages into bio that ultimately get released via bio_release_pages(). Add a new config parameter, CONFIG_BLK_USE_PIN_USER_PAGES_FOR_DIO, and dio_w_*() wrapper functions. The dio_w_ prefix was chosen for uniqueness, so as to ease a subsequent kernel-wide rename via search-and-replace. Together, these allow the developer to choose between these sets of routines, for Direct IO code paths: a) pin_user_pages_fast() pin_user_page() unpin_user_page() b) get_user_pages_fast() get_page() put_page() CONFIG_BLK_USE_PIN_USER_PAGES_FOR_DIO is a temporary setting, and may be deleted once the conversion is complete. In the meantime, developers can enable this in order to try out each filesystem. Please remember that these /proc/vmstat items (below) should normally contain the same values as each other, except during the middle of pin/unpin operations. As such, they can be helpful when monitoring test runs: nr_foll_pin_acquired nr_foll_pin_released Link: https://lkml.kernel.org/r/20220827083607.2345453-3-jhubbard@nvidia.com Signed-off-by: John Hubbard Cc: Alexander Viro Cc: Anna Schumaker Cc: Christoph Hellwig Cc: "Darrick J. Wong" Cc: Jan Kara Cc: Jens Axboe Cc: Logan Gunthorpe Cc: Miklos Szeredi Cc: Trond Myklebust Signed-off-by: Andrew Morton --- block/Kconfig | 24 ++++++++++++++++++++++++ include/linux/bvec.h | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) --- a/block/Kconfig~block-add-dio_w_-wrappers-for-pin-unpin-user-pages +++ a/block/Kconfig @@ -48,6 +48,30 @@ config BLK_DEV_BSG_COMMON config BLK_ICQ bool +config BLK_USE_PIN_USER_PAGES_FOR_DIO + bool "DEVELOPERS ONLY: Enable pin_user_pages() for Direct IO" if EXPERT + default n + + help + For Direct IO code, retain the pages via calls to + pin_user_pages_fast(), instead of via get_user_pages_fast(). + Likewise, use pin_user_page() instead of get_page(). And then + release such pages via unpin_user_page(), instead of + put_page(). + + This is a temporary setting, which will be deleted once the + conversion is completed, reviewed, and tested. In the meantime, + developers can enable this in order to try out each filesystem. + For that, it's best to monitor these /proc/vmstat items: + + nr_foll_pin_acquired + nr_foll_pin_released + + ...to ensure that they remain equal, when "at rest". + + Say yes here ONLY if are actively developing or testing the + block layer or filesystems with pin_user_pages_fast(). + config BLK_DEV_BSGLIB bool "Block layer SG support v4 helper lib" select BLK_DEV_BSG_COMMON --- a/include/linux/bvec.h~block-add-dio_w_-wrappers-for-pin-unpin-user-pages +++ a/include/linux/bvec.h @@ -241,4 +241,44 @@ static inline void *bvec_virt(struct bio return page_address(bvec->bv_page) + bvec->bv_offset; } +#ifdef CONFIG_BLK_USE_PIN_USER_PAGES_FOR_DIO +#define dio_w_pin_user_pages_fast(s, n, p, f) pin_user_pages_fast(s, n, p, f) +#define dio_w_pin_user_page(p) pin_user_page(p) +#define dio_w_iov_iter_pin_pages(i, p, m, n, s) iov_iter_pin_pages(i, p, m, n, s) +#define dio_w_iov_iter_pin_pages_alloc(i, p, m, s) iov_iter_pin_pages_alloc(i, p, m, s) +#define dio_w_unpin_user_page(p) unpin_user_page(p) +#define dio_w_unpin_user_pages(p, n) unpin_user_pages(p, n) +#define dio_w_unpin_user_pages_dirty_lock(p, n, d) unpin_user_pages_dirty_lock(p, n, d) + +#else +#define dio_w_pin_user_pages_fast(s, n, p, f) get_user_pages_fast(s, n, p, f) +#define dio_w_pin_user_page(p) get_page(p) +#define dio_w_iov_iter_pin_pages(i, p, m, n, s) iov_iter_get_pages2(i, p, m, n, s) +#define dio_w_iov_iter_pin_pages_alloc(i, p, m, s) iov_iter_get_pages_alloc2(i, p, m, s) +#define dio_w_unpin_user_page(p) put_page(p) + +static inline void dio_w_unpin_user_pages(struct page **pages, + unsigned long npages) +{ + unsigned long i; + + for (i = 0; i < npages; i++) + put_page(pages[i]); +} + +static inline void dio_w_unpin_user_pages_dirty_lock(struct page **pages, + unsigned long npages, + bool make_dirty) +{ + unsigned long i; + + for (i = 0; i < npages; i++) { + if (make_dirty) + set_page_dirty_lock(pages[i]); + put_page(pages[i]); + } +} + +#endif + #endif /* __LINUX_BVEC_H */ _ Patches currently in -mm which might be from jhubbard@nvidia.com are mm-gup-introduce-pin_user_page.patch block-add-dio_w_-wrappers-for-pin-unpin-user-pages.patch iov_iter-new-iov_iter_pin_pages-routines.patch block-bio-fs-convert-most-filesystems-to-pin_user_pages_fast.patch nfs-direct-io-convert-to-foll_pin-pages.patch fuse-convert-direct-io-paths-to-use-foll_pin.patch