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From: Stephen Hemminger <stephen@networkplumber.org>
To: Michal Sieron <michal.sieron@nokia.com>
Cc: dev@dpdk.org
Subject: Re: [PATCH] linux/mem: atomically prefault hugepages in alloc_seg
Date: Wed, 20 May 2026 10:07:38 -0700	[thread overview]
Message-ID: <20260520100738.7042b965@phoenix.local> (raw)
In-Reply-To: <20260520125756.530808-1-michal.sieron@nokia.com>

On Wed, 20 May 2026 14:57:56 +0200
Michal Sieron <michal.sieron@nokia.com> wrote:

> In rare cases, when a secondary process calls rte_eal_init() it can
> cause a data race during page prefaulting in alloc_seg().
> 
> An atomic compare-exchange in a loop should eliminate the data race.
> 
> Signed-off-by: Michal Sieron <michal.sieron@nokia.com>
> ---

AI had good suggestion when reviewing this.
Your version is still racy (on the read side).

A simple non-racy, and no loop version would be:

	rte_atomic_fetch_or_explicit((int *)addr, 0, rte_memory_order_relaxed);

  parent reply	other threads:[~2026-05-20 17:07 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-20 12:57 [PATCH] linux/mem: atomically prefault hugepages in alloc_seg Michal Sieron
2026-05-20 14:57 ` Stephen Hemminger
2026-05-20 16:47 ` Stephen Hemminger
2026-05-20 17:07 ` Stephen Hemminger [this message]
2026-05-20 17:08 ` [PATCH] eal: fix data race in hugepage prefault Stephen Hemminger
2026-06-01 10:03   ` Thomas Monjalon
2026-06-01 16:00   ` [PATCH v2] " Stephen Hemminger
2026-06-03 15:57     ` Thomas Monjalon

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