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 32002C433FE for ; Wed, 20 Apr 2022 03:24:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359265AbiDTD1O (ORCPT ); Tue, 19 Apr 2022 23:27:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239413AbiDTD1N (ORCPT ); Tue, 19 Apr 2022 23:27:13 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C0D021E13; Tue, 19 Apr 2022 20:24:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1650425068; x=1681961068; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=ABPdNmHHBR0xLY/Ru6EV3J58j73qsnuwoz1VPUML71M=; b=PmUeqC6NglhqYOwwQZTyPjSTIKFIaCW9F8Pg9ELdrMX408heS/7HrFPf 0S1B4VDUrgGqHVzK6R8PNahYofIAgMFJp28duALUcJ1nWcO4mGA+OewN5 HNMjtoSW8A5D3Dtx+tZV/vCjwJgFCXUKG/3M4HBpR7mSHe+mPR4XIicr1 vCqWqlAttn5jgpujFtSA16Y1oQogxJnjl8jOgJ3cpghP3DzG4j/E5mvMm jVx/0hFz7i/NHGk0114DOjGVPyUmudI73PXWDkHFvlfCMAGhGrMkYPxhV 8UeI9p8aGeirJkEQWeREqKJOyYk4DD4IDOWk646A8VHgqLqa9WmGXejtQ A==; X-IronPort-AV: E=McAfee;i="6400,9594,10322"; a="243859398" X-IronPort-AV: E=Sophos;i="5.90,274,1643702400"; d="scan'208";a="243859398" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Apr 2022 20:24:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,274,1643702400"; d="scan'208";a="667599784" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.192.101]) by orsmga004.jf.intel.com with ESMTP; 19 Apr 2022 20:24:19 -0700 Date: Wed, 20 Apr 2022 11:24:10 +0800 From: Chao Peng To: Vishal Annapurve Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, qemu-devel@nongnu.org, Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Yu Zhang , "Kirill A . Shutemov" , Andy Lutomirski , Jun Nakajima , dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: Re: [PATCH v5 03/13] mm/shmem: Support memfile_notifier Message-ID: <20220420032410.GB39591@chaop.bj.intel.com> Reply-To: Chao Peng References: <20220310140911.50924-1-chao.p.peng@linux.intel.com> <20220310140911.50924-4-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 19, 2022 at 03:40:09PM -0700, Vishal Annapurve wrote: > On Thu, Mar 10, 2022 at 6:10 AM Chao Peng wrote: > > > > From: "Kirill A. Shutemov" > > > > It maintains a memfile_notifier list in shmem_inode_info structure and > > implements memfile_pfn_ops callbacks defined by memfile_notifier. It > > then exposes them to memfile_notifier via > > shmem_get_memfile_notifier_info. > > > > We use SGP_NOALLOC in shmem_get_lock_pfn since the pages should be > > allocated by userspace for private memory. If there is no pages > > allocated at the offset then error should be returned so KVM knows that > > the memory is not private memory. > > > > Signed-off-by: Kirill A. Shutemov > > Signed-off-by: Chao Peng > > --- > > include/linux/shmem_fs.h | 4 +++ > > mm/shmem.c | 76 ++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 80 insertions(+) > > > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > > index 2dde843f28ef..7bb16f2d2825 100644 > > --- a/include/linux/shmem_fs.h > > +++ b/include/linux/shmem_fs.h > > @@ -9,6 +9,7 @@ > > #include > > #include > > #include > > +#include > > > > /* inode in-kernel data */ > > > > @@ -28,6 +29,9 @@ struct shmem_inode_info { > > struct simple_xattrs xattrs; /* list of xattrs */ > > atomic_t stop_eviction; /* hold when working on inode */ > > unsigned int xflags; /* shmem extended flags */ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct memfile_notifier_list memfile_notifiers; > > +#endif > > struct inode vfs_inode; > > }; > > > > diff --git a/mm/shmem.c b/mm/shmem.c > > index 9b31a7056009..7b43e274c9a2 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > > return page ? page_folio(page) : NULL; > > } > > > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > > +{ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct shmem_inode_info *info = SHMEM_I(inode); > > + > > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > > +#endif > > +} > > + > > +static void notify_invalidate_page(struct inode *inode, struct folio *folio, > > + pgoff_t start, pgoff_t end) > > +{ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct shmem_inode_info *info = SHMEM_I(inode); > > + > > + start = max(start, folio->index); > > + end = min(end, folio->index + folio_nr_pages(folio)); > > + > > + memfile_notifier_invalidate(&info->memfile_notifiers, start, end); > > +#endif > > +} > > + > > /* > > * Remove range of pages and swap entries from page cache, and free them. > > * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. > > @@ -946,6 +968,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > > } > > index += folio_nr_pages(folio) - 1; > > > > + notify_invalidate_page(inode, folio, start, end); > > + > > if (!unfalloc || !folio_test_uptodate(folio)) > > truncate_inode_folio(mapping, folio); > > folio_unlock(folio); > > @@ -1019,6 +1043,9 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > > index--; > > break; > > } > > + > > + notify_invalidate_page(inode, folio, start, end); > > + > > Should this be done in batches or done once for all of range [start, end)? Batching is definitely prefered. Will look at that. Thanks, Chao > > > VM_BUG_ON_FOLIO(folio_test_writeback(folio), > > folio); > > truncate_inode_folio(mapping, folio); > > @@ -2279,6 +2306,9 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode > > info->flags = flags & VM_NORESERVE; > > INIT_LIST_HEAD(&info->shrinklist); > > INIT_LIST_HEAD(&info->swaplist); > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + memfile_notifier_list_init(&info->memfile_notifiers); > > +#endif > > simple_xattrs_init(&info->xattrs); > > cache_no_acl(inode); > > mapping_set_large_folios(inode->i_mapping); > > @@ -2802,6 +2832,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, > > if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) > > i_size_write(inode, offset + len); > > inode->i_ctime = current_time(inode); > > + notify_fallocate(inode, start, end); > > undone: > > spin_lock(&inode->i_lock); > > inode->i_private = NULL; > > @@ -3909,6 +3940,47 @@ static struct file_system_type shmem_fs_type = { > > .fs_flags = FS_USERNS_MOUNT, > > }; > > > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > +static long shmem_get_lock_pfn(struct inode *inode, pgoff_t offset, int *order) > > +{ > > + struct page *page; > > + int ret; > > + > > + ret = shmem_getpage(inode, offset, &page, SGP_NOALLOC); > > + if (ret) > > + return ret; > > + > > + *order = thp_order(compound_head(page)); > > + > > + return page_to_pfn(page); > > +} > > + > > +static void shmem_put_unlock_pfn(unsigned long pfn) > > +{ > > + struct page *page = pfn_to_page(pfn); > > + > > + VM_BUG_ON_PAGE(!PageLocked(page), page); > > + > > + set_page_dirty(page); > > + unlock_page(page); > > + put_page(page); > > +} > > + > > +static struct memfile_notifier_list* shmem_get_notifier_list(struct inode *inode) > > +{ > > + if (!shmem_mapping(inode->i_mapping)) > > + return NULL; > > + > > + return &SHMEM_I(inode)->memfile_notifiers; > > +} > > + > > +static struct memfile_backing_store shmem_backing_store = { > > + .pfn_ops.get_lock_pfn = shmem_get_lock_pfn, > > + .pfn_ops.put_unlock_pfn = shmem_put_unlock_pfn, > > + .get_notifier_list = shmem_get_notifier_list, > > +}; > > +#endif /* CONFIG_MEMFILE_NOTIFIER */ > > + > > int __init shmem_init(void) > > { > > int error; > > @@ -3934,6 +4006,10 @@ int __init shmem_init(void) > > else > > shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */ > > #endif > > + > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + memfile_register_backing_store(&shmem_backing_store); > > +#endif > > return 0; > > > > out1: > > -- > > 2.17.1 > >