From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Jianfeng Tan <jianfeng.tan@intel.com>
Cc: dev@dpdk.org, huawei.xie@intel.com
Subject: Re: [dpdk-dev] [PATCH] virtio: fix allocating virtnet_rx not mem aligned
Date: Mon, 13 Jun 2016 17:21:01 +0800 [thread overview]
Message-ID: <20160613092101.GN10038@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <1465741782-126976-1-git-send-email-jianfeng.tan@intel.com>
On Sun, Jun 12, 2016 at 02:29:42PM +0000, Jianfeng Tan wrote:
> Compile DPDK with clang, below line in virtio_rxtx.c could be
> optimized with four "VMOVAPS ymm, m256".
> memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
>
> This instruction requires memory address is 32-byte aligned.
> Or, it leads to segfault.
That looks like a dangerous optimization to me. If that's the case,
doesn't it mean we have to make sure the address is always aligned
properly while calling memset?
--yliu
next prev parent reply other threads:[~2016-06-13 9:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-12 14:29 Jianfeng Tan
2016-06-13 9:21 ` Yuanhan Liu [this message]
2016-06-13 9:51 ` Yuanhan Liu
2016-06-13 10:06 ` Tan, Jianfeng
2016-06-13 10:26 ` Yuanhan Liu
2016-06-13 10:15 ` Tan, Jianfeng
2016-06-14 12:44 ` Yuanhan Liu
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