From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-devel@nongnu.org, qemu-stable@nongnu.org
Subject: Re: [PATCH] util/interval-tree: Avoid race conditions without optimization
Date: Thu, 13 Jul 2023 16:42:51 +0100 [thread overview]
Message-ID: <0c7c6e95-e727-85c9-8fb5-928d9a420de8@linaro.org> (raw)
In-Reply-To: <CAFEAcA9LF_7RKSut0=XrLOnWx9ag7b7R0vWongxBb1dUiHjM0g@mail.gmail.com>
On 7/13/23 12:32, Peter Maydell wrote:
> On Fri, 7 Jul 2023 at 11:30, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> Read the left and right trees once, so that the gating
>> tests are meaningful. This was only a problem at -O0,
>> where the compiler didn't CSE the two reads.
>>
>> Cc: qemu-stable@nongnu.org
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>
> If this data structure is intended to support operations
> being done on it while it's being mutated, shouldn't it
> be using the atomic accessors, though? That would make
> it clearer that you can't just undo the transformation
> made by this patch.
Yes, it probably should. I use qatomic_set() where the kernel used WRITE_ONCE, but there
was no markup for the read side.
r~
prev parent reply other threads:[~2023-07-13 15:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-07 10:30 [PATCH] util/interval-tree: Avoid race conditions without optimization Richard Henderson
2023-07-13 11:32 ` Peter Maydell
2023-07-13 15:42 ` Richard Henderson [this message]
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