From: Christoph Hellwig <hch@infradead.org>
To: Nikolay Borisov <nborisov@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Pavel Reichl <preichl@redhat.com>,
linux-xfs@vger.kernel.org, david@fromorbit.com
Subject: Re: [RFC PATCH 0/3] Remove mrlock
Date: Wed, 13 Jan 2021 12:09:14 +0000 [thread overview]
Message-ID: <20210113120914.GA1482951@infradead.org> (raw)
In-Reply-To: <3b68fb68-f11f-1c50-a350-28159c003afe@suse.com>
On Wed, Jan 13, 2021 at 01:41:09PM +0200, Nikolay Borisov wrote:
>
>
> On 13.01.21 ??. 13:27 ??., Christoph Hellwig wrote:
> > Pavel has looked into this before and got stuck on the allocator
> > workqueue offloads:
> >
> > [PATCH v13 0/4] xfs: Remove wrappers for some semaphores
>
> I haven't looked into his series but I fail to see how lifting
> rwsemaphore out of the nested structure can change the behavior ? It
> just removes a level of indirection. My patches are semantically
> identical to the original code.
mrlocks have the mr_writer field that annotate that the is a writer
locking the lock. The XFS asserts use it to assert that the lock that
the current thread holds it for exclusive protection, which isn't
actually what the field says, and this breaks when XFS uses synchronous
execution of work_struct as basically an extension of the kernel stack.
next prev parent reply other threads:[~2021-01-13 12:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 11:17 [RFC PATCH 0/3] Remove mrlock Nikolay Borisov
2021-01-13 11:17 ` [RFC PATCH 1/3] xfs: Add is_rwsem_write_locked function Nikolay Borisov
2021-01-13 11:17 ` [RFC PATCH 2/3] xfs: Convert i_lock/i_mmaplock to rw_semaphore Nikolay Borisov
2021-01-13 11:17 ` [RFC PATCH 3/3] xfs: Remove mrlock Nikolay Borisov
2021-01-13 11:17 ` Nikolay Borisov
2021-01-13 11:27 ` [RFC PATCH 0/3] " Christoph Hellwig
2021-01-13 11:41 ` Nikolay Borisov
2021-01-13 12:09 ` Christoph Hellwig [this message]
2021-01-13 12:17 ` Nikolay Borisov
2021-01-20 20:14 ` Darrick J. Wong
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=20210113120914.GA1482951@infradead.org \
--to=hch@infradead.org \
--cc=david@fromorbit.com \
--cc=linux-xfs@vger.kernel.org \
--cc=nborisov@suse.com \
--cc=preichl@redhat.com \
/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).