From: "Jürgen Groß" <jgross@suse.com>
To: SeongJae Park <sjpark@amazon.com>,
axboe@kernel.dk, konrad.wilk@oracle.com, roger.pau@citrix.com
Cc: SeongJae Park <sjpark@amazon.de>,
pdurrant@amazon.com, sj38.park@gmail.com,
xen-devel@lists.xenproject.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v12 2/5] xenbus/backend: Protect xenbus callback with lock
Date: Wed, 18 Dec 2019 13:27:37 +0100 [thread overview]
Message-ID: <af02058a-fa76-5eb5-5c2b-60555273bac2@suse.com> (raw)
In-Reply-To: <20191218104232.9606-3-sjpark@amazon.com>
On 18.12.19 11:42, SeongJae Park wrote:
> From: SeongJae Park <sjpark@amazon.de>
>
> 'reclaim_memory' callback can race with a driver code as this callback
> will be called from any memory pressure detected context. To deal with
> the case, this commit adds a spinlock in the 'xenbus_device'. Whenever
> 'reclaim_memory' callback is called, the lock of the device which passed
> to the callback as its argument is locked. Thus, drivers registering
> their 'reclaim_memory' callback should protect the data that might race
> with the callback with the lock by themselves.
Any reason you don't take the lock around the .probe() and .remove()
calls of the backend (xenbus_dev_probe() and xenbus_dev_remove())? This
would eliminate the need to do that in each backend instead.
Juergen
next prev parent reply other threads:[~2019-12-18 12:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-18 10:42 [PATCH v12 0/5] xenbus/backend: Add memory pressure handler callback SeongJae Park
2019-12-18 10:42 ` [PATCH v12 1/5] " SeongJae Park
2019-12-18 10:42 ` [PATCH v12 2/5] xenbus/backend: Protect xenbus callback with lock SeongJae Park
2019-12-18 12:27 ` Jürgen Groß [this message]
2019-12-18 12:42 ` Re: [Xen-devel] " SeongJae Park
2019-12-18 13:30 ` Jürgen Groß
2019-12-18 14:40 ` SeongJae Park
2019-12-18 15:11 ` Jürgen Groß
2019-12-18 17:32 ` SeongJae Park
2019-12-18 10:42 ` [PATCH v12 3/5] xen/blkback: Squeeze page pools if a memory pressure is detected SeongJae Park
2019-12-18 10:42 ` [PATCH v12 4/5] xen/blkback: Remove unnecessary static variable name prefixes SeongJae Park
2019-12-18 10:44 ` [PATCH v12 5/5] xen/blkback: Consistently insert one empty line between functions SeongJae Park
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