[0/23,v2] mm: Speedup page cache truncation

Message ID	20200422150256.23473-1-jack@suse.cz (mailing list archive)
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 0/23 v2] mm: Speedup page cache truncation Date: Wed, 22 Apr 2020 17:02:33 +0200 Message-Id: <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()

Message ID

20200422150256.23473-1-jack@suse.cz (mailing list archive)

Headers

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 0/23 v2] mm: Speedup page cache truncation
Date: Wed, 22 Apr 2020 17:02:33 +0200
Message-Id: <20200422150256.23473-1-jack@suse.cz>
Sender: linux-fsdevel-owner@vger.kernel.org
Precedence: bulk

Series

mm: Speedup page cache truncation | expand

Message

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

Hello,

this is a second version of my patches to avoid clearing marks from xas_store()
and thus fix regression in page cache truncation.

Changes since v1
- rebased on 5.7-rc2
- drop xas_for_each_marked() fix as it was already merged
- reworked the whole series based on Matthew's feedback - we now create new
  function xas_store_noinit() and use it instead of changing xas_store()
  behavior. Note that for xas_store_range() and __xa_cmpxchg() I didn't bother
  to change names although they stop clearing marks as well. This is because
  there are only very few callers so it's easy to verify them, also chances of
  a clash with other patch introducing new callers are very small.

Original motivation:

Conversion of page cache to xarray (commit 69b6c1319b6 "mm: Convert truncate to
XArray" in particular) has regressed performance of page cache truncation
by about 10% (see my original report here [1]). This patch series aims at
improving the truncation to get some of that regression back.

The first patch fixes a long standing bug with xas_for_each_marked() that I've
uncovered when debugging my patches. The remaining patches then work towards
the ability to stop clearing marks in xas_store() which improves truncation
performance by about 6%.

The patches have passed radix_tree tests in tools/testing and also fstests runs
for ext4 & xfs.

								Honza

[1] https://lore.kernel.org/linux-mm/20190226165628.GB24711@quack2.suse.cz