From: David Howells <dhowells@redhat.com>
To: Hou Tao <houtao@huaweicloud.com>
Cc: dhowells@redhat.com, linux-cachefs@redhat.com,
Jeff Layton <jlayton@kernel.org>,
linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org,
"houtao1@huawei.com" <houtao1@huawei.com>
Subject: Re: [PATCH] fscache: Use wake_up_var() to wake up pending volume acquisition
Date: Fri, 09 Dec 2022 11:26:51 +0000 [thread overview]
Message-ID: <2308529.1670585211@warthog.procyon.org.uk> (raw)
In-Reply-To: <42b33792-50e9-77d7-4d3e-ac5ce1adeda6@huaweicloud.com>
Hou Tao <houtao@huaweicloud.com> wrote:
> > clear_bit(FSCACHE_VOLUME_ACQUIRE_PENDING, &cursor->flags);
Maybe this should be clear_bit_unlock() instead.
And I wonder if:
set_bit(FSCACHE_VOLUME_ACQUIRE_PENDING, &candidate->flags);
in fscache_hash_volume() needs a barrier before it.
> > - wake_up_bit(&cursor->flags, FSCACHE_VOLUME_ACQUIRE_PENDING);
> > + /*
> > + * Paired with barrier in wait_var_event(). Check
> > + * waitqueue_active() and wake_up_var() for details.
> > + */
> > + smp_mb__after_atomic();
> > + wake_up_var(&cursor->flags);
That doesn't seem right.
wake_up_bit() is more selective, so should be preferred to wake_up_var().
David
next prev parent reply other threads:[~2022-12-09 11:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-28 3:19 Hou Tao
2022-11-28 7:56 ` Jingbo Xu
2022-12-09 11:17 ` Hou Tao
2022-12-09 11:26 ` David Howells [this message]
2022-12-15 8:28 ` Hou Tao
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