public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Gao Xiang <gaoxiang25@huawei.com>
Cc: devel@driverdev.osuosl.org, linux-erofs@lists.ozlabs.org,
	Chao Yu <yuchao0@huawei.com>, LKML <linux-kernel@vger.kernel.org>,
	weidu.du@huawei.com, Miao Xie <miaoxie@huawei.com>
Subject: Re: [PATCH 04/10] staging: erofs: fix `erofs_workgroup_{try_to_freeze, unfreeze}'
Date: Thu, 22 Nov 2018 11:21:55 +0100	[thread overview]
Message-ID: <20181122102155.GE3189@kroah.com> (raw)
In-Reply-To: <20181120143425.43637-5-gaoxiang25@huawei.com>

On Tue, Nov 20, 2018 at 10:34:19PM +0800, Gao Xiang wrote:
> There are two minor issues in the current freeze interface:
> 
>    1) Freeze interfaces have not related with CONFIG_DEBUG_SPINLOCK,
>       therefore fix the incorrect conditions;
> 
>    2) For SMP platforms, it should also disable preemption before
>       doing atomic_cmpxchg in case that some high priority tasks
>       preempt between atomic_cmpxchg and disable_preempt, then spin
>       on the locked refcount later.

spinning on a refcount implies that you are trying to do your own type
of locking.  Why not use the in-kernel locking api instead?  It will
always do better than trying to do your own logic as the developers
there know locking across all types of cpus better than filesystem
developers :)

thanks,

greg k-h

  reply	other threads:[~2018-11-22 10:22 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-20 14:34 [PATCH 00/10] staging: erofs: decompression stability enhancement Gao Xiang
2018-11-20 14:34 ` [PATCH 01/10] staging: erofs: fix `trace_erofs_readpage' position Gao Xiang
2018-11-22 10:19   ` Greg Kroah-Hartman
2018-11-22 10:49     ` Gao Xiang
2018-11-22 11:00       ` Greg Kroah-Hartman
2018-11-20 14:34 ` [PATCH 02/10] staging: erofs: fix race when the managed cache is enabled Gao Xiang
2018-11-22 10:17   ` Greg Kroah-Hartman
2018-11-22 10:42     ` Gao Xiang
2018-11-22 11:06       ` Greg Kroah-Hartman
2018-11-22 11:43         ` Gao Xiang
2018-11-22 12:26           ` Greg Kroah-Hartman
2018-11-22 12:41             ` Gao Xiang
2018-11-22 13:20               ` Greg Kroah-Hartman
2018-11-22 10:19   ` Greg Kroah-Hartman
2018-11-20 14:34 ` [PATCH 03/10] staging: erofs: atomic_cond_read_relaxed on ref-locked workgroup Gao Xiang
2018-11-22 10:20   ` Greg Kroah-Hartman
2018-11-20 14:34 ` [PATCH 04/10] staging: erofs: fix `erofs_workgroup_{try_to_freeze, unfreeze}' Gao Xiang
2018-11-22 10:21   ` Greg Kroah-Hartman [this message]
2018-11-22 10:29     ` Gao Xiang
2018-11-22 11:03       ` Greg Kroah-Hartman
2018-11-22 11:05       ` Greg Kroah-Hartman
2018-11-22 11:22         ` Gao Xiang
2018-11-20 14:34 ` [PATCH 05/10] staging: erofs: add a full barrier in erofs_workgroup_unfreeze Gao Xiang
2018-11-22 10:22   ` Greg Kroah-Hartman
2018-11-22 10:56     ` Gao Xiang
2018-11-22 18:50       ` Andrea Parri
2018-11-23  2:51         ` Gao Xiang
2018-11-23  9:51           ` Andrea Parri
2018-11-23 10:00             ` Gao Xiang
2018-11-20 14:34 ` [PATCH 06/10] staging: erofs: fix the definition of DBG_BUGON Gao Xiang
2018-11-20 14:34 ` [PATCH 07/10] staging: erofs: separate into init_once / always Gao Xiang
2018-11-22 10:23   ` Greg Kroah-Hartman
2018-11-22 10:34     ` Gao Xiang
2018-11-22 11:05       ` Greg Kroah-Hartman
2018-11-22 11:11         ` Gao Xiang
2018-11-22 11:26           ` Greg Kroah-Hartman
2018-11-22 11:37             ` Gao Xiang
2018-11-22 12:00             ` Gao Xiang
2018-11-22 13:01               ` Gao Xiang
2018-11-22 13:23                 ` Greg Kroah-Hartman
2018-11-22 13:59                   ` Gao Xiang
2018-11-20 14:34 ` [PATCH 08/10] staging: erofs: locked before registering for all new workgroups Gao Xiang
2018-11-22 10:24   ` Greg Kroah-Hartman
2018-11-22 10:35     ` Gao Xiang
2018-11-20 14:34 ` [PATCH 09/10] staging: erofs: decompress asynchronously if PG_readahead page at first Gao Xiang
2018-11-20 14:34 ` [PATCH 10/10] staging: erofs: rename strange variable names in z_erofs_vle_frontend Gao Xiang

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=20181122102155.GE3189@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=devel@driverdev.osuosl.org \
    --cc=gaoxiang25@huawei.com \
    --cc=linux-erofs@lists.ozlabs.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=miaoxie@huawei.com \
    --cc=weidu.du@huawei.com \
    --cc=yuchao0@huawei.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