From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 82F612101B3 for ; Fri, 1 Aug 2025 21:05:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754082307; cv=none; b=NWf7ri7kCTS9ws6PcfqGGWYWQUoCy3Oi7JpfPxxBGob2cc9AOmHPCkflpdRepIhxyY7jj3jAzIl2AMvrxzNbnHdV+aEnH6IwKZWf7lrzCyWzffRdnEMghvAxQX9oQaLoe5gkwiwI4JBdJMfKVggyrArM+Hx/Magj3AFUCAYXH4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754082307; c=relaxed/simple; bh=JZoyAST6+OVTTphG6ee2gzu1er796wvSDXhYeGpIXYo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LjfTEvIXDvrh80p3H8FGy2OSMOJAainMn2v+I6d6JDGfiy7R+mJqgOL6FQMlHWtrckJzmhMllz7SJOrnNsHZSVvACkaPs6z2BF2xrTTQKtH1dHQPH9L+jpQm/kdWFbO9gzel+3a7LLppfDg0/yAbZrmPcTLj4OUNmh5pWk2Uujg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a12Th1H9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a12Th1H9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1571C4CEE7; Fri, 1 Aug 2025 21:05:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754082307; bh=JZoyAST6+OVTTphG6ee2gzu1er796wvSDXhYeGpIXYo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=a12Th1H9SU84ANeXE6RWjoDNGIdzwPxBkj2yUU4qCCj+vWGQn6wxlwFN1gs3RoPxg WEYyV0yAkIeNp+fLhr2QaIEOAm0tpBd4DXHncyDQS6yRva6OS0AJFV1BWON7EBB5cF eanxdoGtSDU8/2idCWxTgMTr5YWmLn/je759+TGll0EFIKijXWlZWAkkRHwj7nrXAz 2E/u/jKHY88fOkpV0oLp6DM3nCAFNLeW8jUGGB1f53Jz/+B8T0fPcIcM+NDF/Gb9qD xKntdNmB87bV1LaPPL4DayphdxXgxTiq0nkrrsSPRhm5H5oC05YjJ32pX0KalYmFmt oRMycu3lcHvHA== Date: Fri, 1 Aug 2025 14:05:06 -0700 From: Jakub Kicinski To: Stanislav Fomichev Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, David Wei , michael.chan@broadcom.com, pavan.chebbi@broadcom.com, hawk@kernel.org, ilias.apalodimas@linaro.org, almasrymina@google.com, sdf@fomichev.me Subject: Re: [PATCH net] net: page_pool: allow enabling recycling late, fix false positive warning Message-ID: <20250801140506.5b3e7213@kernel.org> In-Reply-To: References: <20250801173011.2454447-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 1 Aug 2025 13:55:09 -0700 Stanislav Fomichev wrote: > > +static void bnxt_enable_rx_page_pool(struct bnxt_rx_ring_info *rxr) > > +{ > > + page_pool_enable_direct_recycling(rxr->head_pool, &rxr->bnapi->napi); > > + page_pool_enable_direct_recycling(rxr->page_pool, &rxr->bnapi->napi); > > We do bnxt_separate_head_pool check for the disable_direct_recycling > of head_pool. Is it safe to skip the check here because we always allocate two > pps from queue_mgmt callbacks? (not clear for me from a quick glance at > bnxt_alloc_rx_page_pool) It's safe (I hope) because the helper is duplicate-call-friendly: +void page_pool_enable_direct_recycling(struct page_pool *pool, + struct napi_struct *napi) +{ + if (READ_ONCE(pool->p.napi) == napi) <<< right here + return; + WARN_ON_ONCE(!napi || pool->p.napi); + + mutex_lock(&page_pools_lock); + WRITE_ONCE(pool->p.napi, napi); + mutex_unlock(&page_pools_lock); +} We already have a refcount in page pool, I'm planning to add page_pool_get() in net-next and remove the if (bnxt_separate_head_pool) before page_pool_destroy(), too.