diff mbox series

[09/23] dax: Use dax_store_noinit() in grab_mapping_entry()

Message ID	20200422150256.23473-10-jack@suse.cz (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=GpHg=6G=vger.kernel.org=linux-fsdevel-owner@kernel.org> From: Jan Kara <jack@suse.cz> To: Matthew Wilcox <willy@infradead.org> Cc: <linux-fsdevel@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, Jan Kara <jack@suse.cz> Subject: [PATCH 09/23] dax: Use dax_store_noinit() in grab_mapping_entry() Date: Wed, 22 Apr 2020 17:02:42 +0200 Message-Id: <20200422150256.23473-10-jack@suse.cz> In-Reply-To: <20200422150256.23473-1-jack@suse.cz> References: <20200422150256.23473-1-jack@suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk
Series	mm: Speedup page cache truncation \| expand [0/23,v2] mm: Speedup page cache truncation [01/23] xarray: Remove stale comment [02/23] xarray: Provide xas_erase() and xas_store_noinit() helpers [03/23] xarray: Use xas_store_noinit() in __xa_store, __xa_insert, __xa_alloc [04/23] xarray: Switch xa_store_range() to use xas_store_noinit() [05/23] xarray: Use xas_erase() in __xa_erase() [06/23] xarray: Explicitely set XA_FREE_MARK in __xa_cmpxchg() [07/23] xarray: Switch __xa_cmpxchg() to use xas_store_noinit() [08/23] dax: Use xas_erase() in __dax_invalidate_entry() [09/23] dax: Use dax_store_noinit() in grab_mapping_entry() [10/23] dax: Convert xas_store() to xas_store_noinit() [11/23] mm: Use xas_erase() in page_cache_delete_batch() [12/23] mm: Use xas_erase() in collapse_file() [13/23] mm: Use xas_store_noinit() when storing non-NULL [14/23] workingset: Use xas_store_noinit() to clear shadow entry [15/23] swap: Use xas_erase() when removing page from swap cache [16/23] idr: Use xas_erase() in ida_destroy() [17/23] idr: Use xas_erase() in ida_free() [18/23] idr: Convert xas_store() to xas_store_noinit() [19/23] testing: Use xas_erase() to remove entries from xarray [20/23] testing: Use xas_store_noinit() for non-NULL entries [21/23] testing: Introduce xa_erase_order() and use it [22/23] testing: Switch xa_store_order() to xas_store_noinit() [23/23] xarray: Remove xas_store()

Commit Message

Jan Kara April 22, 2020, 3:02 p.m. UTC

Although we store NULL here, there aren't any marks set on the entry
so use xas_store_noinit() to save some time when trying to reinitialize
marks. Furthermore we actually overwrite the entry shortly afterwards
with new PTE entry anyway.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/dax.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff mbox series

Patch

diff --git a/fs/dax.c b/fs/dax.c
index f8358928549c..03c6ca693f3c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -523,7 +523,11 @@  static void *grab_mapping_entry(struct xa_state *xas,
 		}
 
 		dax_disassociate_entry(entry, mapping, false);
-		xas_store(xas, NULL);	/* undo the PMD join */
+		/*
+		 * Remove PMD entry. There should be no marks set for the entry
+ 		 * so don't bother reinitializing them with xas_erase().
+		 */
+		xas_store_noinit(xas, NULL);
 		dax_wake_entry(xas, entry, true);
 		mapping->nrexceptional--;
 		entry = NULL;