From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BF4822C11C4; Fri, 17 Jul 2026 13:48:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784296092; cv=none; b=adJj2q7r8sFwtx3Y5o7tlQTfT28fQFtfHBXCdfN1cnwD8SArmufW4doKpLMxNSWHMinPJXKQX5qnHPMJKeA7CE+eofZXP02iBW1NiaPW32ix8anjGmkiRxxRr6Tx0DtQY8dO8OYDPGdHTmUsFXcbXJP1G6+4HUqFt8x862frfH4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784296092; c=relaxed/simple; bh=SDjLLjLjj/PY7dj+tDmmUJVM2sPanb6HqHVWg9VdznI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NClnlifL6JxUbSG4xpOYwLQJJSqCkVvMV6jykJhXWC2OAEDdNdtH2xXLVzI8c3MW9VMlamQJr9acaIxOhWXeGeJ5u/P0S1Th77Bs6wG4juVXcegPCz6GdKI8IO4F6flYQ67noZZJPXi01geF5rP4eJjlUUNBp3BDTRM5dJfag+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=i5wS+SS9; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="i5wS+SS9" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=IE/uhBfHarutxeKsGlFRc4pf5fz0ECUu1pnbHJvzzbg=; b=i5wS+SS99JRiIVgCgXJbu7Lx8+ JO1r2mq7mWUsTp17zWs8UXsKrUNqavmcJfBP1YGf03CbAVsVYSzcry38abdDRghVcTMrZawjQOo4B TmGWM9POTKFC2oNYlPCRzhirmoai5P2wumjfzDKS1id8/IjKo4ZXjaKx7bP9ucXEtsB/KbOd142At jPqXC/tcHkdhyQ9NHPh7HaNU5hc8UqJU/8xFds3A+E659u6DPpq9gSZLns9wcsm5OTTrmN1VmgHAi VIU8VmBImXZP8hTSlEgskHnAJ92WTt9rOZpGT6PJ5IIcEVgNSFMw3umaYOznANxA0YJZ5e8Lzo0/t IRY4Pb0g==; Received: from willy by casper.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkiuv-000000056zw-3SKZ; Fri, 17 Jul 2026 13:47:53 +0000 Date: Fri, 17 Jul 2026 14:47:53 +0100 From: Matthew Wilcox To: Eric Dumazet Cc: Usama Arif , Breno Leitao , davem@davemloft.net, horms@kernel.org, kuba@kernel.org, kuniyu@google.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, willemb@google.com, shakeel.butt@linux.dev, hannes@cmpxchg.org, riel@surriel.com, kernel-team@meta.com Subject: Re: [PATCH] net: use sync wakeups for socket error reports Message-ID: References: <20260708133815.3419465-1-usama.arif@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, Jul 08, 2026 at 06:32:02PM +0200, Eric Dumazet wrote: > On Wed, Jul 8, 2026 at 6:09 PM Usama Arif wrote: > > So the workload has SO_TIMESTAMPING enabled on its TCP sockets, and every > > packet completion and every ACK triggers a timestamp delivery through the > > error-queue path, which is why sock_def_error_report fires. > > It seems we can not please everyone. > > https://lore.kernel.org/netdev/20260526063650.952-1-xuewen.yan@unisoc.com/ > > Perhaps this SYNC heuristic should be a per-socket choice so that > applications can decide what is best for them. Instead of adding a new socket option, perhaps use SO_TIMESTAMPING to decide whether to use sync or not? There could be other socket options which also report a high rate of "errors", but until those show up I think just testing on this one socket option should be fine.