From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH v14 00/74] Convert page cache to XArray Date: Wed, 27 Jun 2018 04:05:29 -0700 Message-ID: <20180627110529.GA19606@bombadil.infradead.org> References: <20180617020052.4759-1-willy@infradead.org> <20180619031257.GA12527@linux.intel.com> <20180619092230.GA1438@bombadil.infradead.org> <20180619164037.GA6679@linux.intel.com> <20180619171638.GE1438@bombadil.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=In-Reply-To:Content-Type:MIME-Version:References: Message-ID:Subject:To:From:Date:Sender:Reply-To:Cc:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=AAlExSFvFVxQo8Umv+Bv+kndvRO1cNE2u5Zfi2qlroU=; b=ekfVTTHwYtstQGoAaLo/XbgDKr uEUW/EzDAmETTr0tSOYtaMnb6537geVgLF0IVs7FS3LyfMRhzPOMKnqC/40/+CnjsHM4YlrirNtFF bKzpxKlUnRZTlvQ5h4Hb8W839dNvtQX6qcJ40wCbn2Hvb3M4y2/fk1EAxxEP2SBIitfQ=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:To: From:Date:Sender:Reply-To:Cc:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=AAlExSFvFVxQo8Umv+Bv+kndvRO1cNE2u5Zfi2qlroU=; b=WL5x119n2+ks1cAygmpZyXPV72 6XhMMPhQ0tLEtPkbN95bm8OUe66oGAxTvUKEpDTt+cf7epw5w5baYsQ7BvxH+VgesRAtBqFxl3gOS uzociqQ/3obRJNrI70XWouAgB0M8su1162Q9CP3Dkj3tDO0sLrVtA5v4szx/b5c1NRTg=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:To:From:Date:Sender:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=AAlExSFvFVxQo8Umv+Bv+kndvRO1cNE2u5Zfi2qlroU=; b=glmVDMt45pfxpDWnWVSBQ0Aab l7me4qHFaH2HJzvMynUprc/NyGAXlkyq6TyRwSroV7mu1Oczni0MCMFvDZk0dH8SX53z2IqKBi7bY Qm9vbGc5L73nnJut9FAU0Lf4JH+DpQbftr76NOYx5tkH8/xPIL4146oM6/nirinxusEAKCRt8nY2Y t15pQsuDof3eAq8s81IodNun/Q5kBwG4IiYSc2QOKg9aKasY6nL0gl5/zbyh4emFJNa1yCvrKZb6O C5BdYobNlS1Pfdb+Hrzb2sBnQnzGebn8RCyuJ7bVmQ4XDoV5idK6ywPLpFvMs9ootG9djDhnOt3WZ SMD3y2wgw==; Content-Disposition: inline In-Reply-To: <20180619171638.GE1438@bombadil.infradead.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Ross Zwisler , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Jan Kara , Jeff Layton , Lukas Czerner , Christoph Hellwig , Goldwyn Rodrigues , Nicholas Piggin , Ryusuke Konishi , linux-nilfs@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net On Tue, Jun 19, 2018 at 10:16:38AM -0700, Matthew Wilcox wrote: > I think I see a bug. No idea if it's the one you're hitting ;-) > > I had been intending to not use the 'entry' to decide whether we were > waiting on a 2MB or 4kB page, but rather the xas. I shelved that idea, > but not before dropping the DAX_PMD flag being passed from the PMD > pagefault caller. So if I put that back ... Did you get a chance to test this? > diff --git a/fs/dax.c b/fs/dax.c > index 9919b6b545fb..75cc160d2f0b 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -367,13 +367,13 @@ static struct page *dax_busy_page(void *entry) > * a VM_FAULT code, encoded as an xarray internal entry. The ERR_PTR values > * overlap with xarray value entries. > */ > -static > -void *grab_mapping_entry(struct xa_state *xas, struct address_space *mapping) > +static void *grab_mapping_entry(struct xa_state *xas, > + struct address_space *mapping, unsigned long size) > { > bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */ > void *locked = dax_make_entry(pfn_to_pfn_t(0), > - DAX_EMPTY | DAX_LOCKED); > - void *unlocked = dax_make_entry(pfn_to_pfn_t(0), DAX_EMPTY); > + size | DAX_EMPTY | DAX_LOCKED); > + void *unlocked = dax_make_entry(pfn_to_pfn_t(0), size | DAX_EMPTY); > void *entry; > > retry: > @@ -1163,7 +1163,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, > if (write && !vmf->cow_page) > flags |= IOMAP_WRITE; > > - entry = grab_mapping_entry(&xas, mapping); > + entry = grab_mapping_entry(&xas, mapping, 0); > if (xa_is_internal(entry)) { > ret = xa_to_internal(entry); > goto out; > @@ -1396,7 +1396,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, > * page is already in the tree, for instance), it will return > * VM_FAULT_FALLBACK. > */ > - entry = grab_mapping_entry(&xas, mapping); > + entry = grab_mapping_entry(&xas, mapping, DAX_PMD); > if (xa_is_internal(entry)) { > result = xa_to_internal(entry); > goto fallback; > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot