linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 3/8] xarray: Explicitely set XA_FREE_MARK in __xa_cmpxchg()
Date: Wed, 5 Feb 2020 14:45:12 -0400	[thread overview]
Message-ID: <20200205184512.GC28298@ziepe.ca> (raw)
In-Reply-To: <20200204142514.15826-4-jack@suse.cz>

On Tue, Feb 04, 2020 at 03:25:09PM +0100, Jan Kara wrote:
> __xa_cmpxchg() relies on xas_store() to set XA_FREE_MARK when storing
> NULL into xarray that has free tracking enabled. Make the setting of
> XA_FREE_MARK explicit similarly as its clearing currently it.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>
>  lib/xarray.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/xarray.c b/lib/xarray.c
> index ae8b7070e82c..4e32497c51bd 100644
> +++ b/lib/xarray.c
> @@ -1477,8 +1477,12 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
>  		curr = xas_load(&xas);
>  		if (curr == old) {
>  			xas_store(&xas, entry);
> -			if (xa_track_free(xa) && entry && !curr)
> -				xas_clear_mark(&xas, XA_FREE_MARK);
> +			if (xa_track_free(xa)) {
> +				if (entry && !curr)
> +					xas_clear_mark(&xas, XA_FREE_MARK);
> +				else if (!entry && curr)
> +					xas_set_mark(&xas, XA_FREE_MARK);
> +			}

This feels like an optimization that should also happen for
__xa_store, which has very similar code:

		curr = xas_store(&xas, entry);
		if (xa_track_free(xa))
			xas_clear_mark(&xas, XA_FREE_MARK);

Something like

                if (xa_track_free(xa) && entry && !curr)
			xas_clear_mark(&xas, XA_FREE_MARK);

?

Regards,
Jason


  reply	other threads:[~2020-02-05 18:45 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-04 14:25 [PATCH 0/8] mm: Speedup page cache truncation Jan Kara
2020-02-04 14:25 ` [PATCH 1/8] xarray: Fix premature termination of xas_for_each_marked() Jan Kara
2020-03-12 21:45   ` Matthew Wilcox
2020-03-16  9:16     ` Jan Kara
2020-02-04 14:25 ` [PATCH 2/8] xarray: Provide xas_erase() helper Jan Kara
2020-03-14 19:54   ` Matthew Wilcox
2020-03-16  9:21     ` Jan Kara
2020-03-17 15:28   ` Matthew Wilcox
2020-04-15 16:12     ` Jan Kara
2020-02-04 14:25 ` [PATCH 3/8] xarray: Explicitely set XA_FREE_MARK in __xa_cmpxchg() Jan Kara
2020-02-05 18:45   ` Jason Gunthorpe [this message]
2020-02-06  8:03     ` Jan Kara
2020-03-17 15:12   ` Matthew Wilcox
2020-02-04 14:25 ` [PATCH 4/8] mm: Use xas_erase() in page_cache_delete_batch() Jan Kara
2020-02-04 14:25 ` [PATCH 5/8] dax: Use xas_erase() in __dax_invalidate_entry() Jan Kara
2020-02-04 14:25 ` [PATCH 6/8] idr: Use xas_erase() in ida_destroy() Jan Kara
2020-02-04 14:25 ` [PATCH 7/8] mm: Use xas_erase() in collapse_file() Jan Kara
2020-02-04 14:25 ` [PATCH 8/8] xarray: Don't clear marks in xas_store() Jan Kara
2020-02-05 18:43   ` Jason Gunthorpe
2020-02-05 21:59     ` Matthew Wilcox
2020-02-06 13:49       ` Jason Gunthorpe
2020-02-06 14:36         ` Jan Kara
2020-02-06 14:49           ` Jason Gunthorpe
2020-02-05 22:19   ` John Hubbard
2020-02-06  2:21     ` Matthew Wilcox
2020-02-06  3:48       ` John Hubbard
2020-02-06  4:28         ` Matthew Wilcox
2020-02-06  4:37           ` John Hubbard
2020-02-06  8:36           ` Jan Kara
2020-02-06  8:04     ` Jan Kara
2020-02-06 14:40 ` [PATCH 0/8] mm: Speedup page cache truncation David Sterba
2020-02-18  9:25 ` Jan Kara

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200205184512.GC28298@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=jack@suse.cz \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).