From: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
To: netdev@vger.kernel.org,
Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>,
Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Subject: Re: [PATCH net-next 5/5] sunvnet: Use kmap_local_page() instead of kmap_atomic()
Date: Fri, 18 Nov 2022 10:11:12 +0100 [thread overview]
Message-ID: <2373606.NG923GbCHz@suse> (raw)
In-Reply-To: <20221117222557.2196195-6-anirudh.venkataramanan@intel.com>
On giovedì 17 novembre 2022 23:25:57 CET Anirudh Venkataramanan wrote:
> kmap_atomic() is being deprecated in favor of kmap_local_page().
> Replace kmap_atomic() and kunmap_atomic() with kmap_local_page()
> and kunmap_local() respectively.
>
> Note that kmap_atomic() disables preemption and page-fault processing,
> but kmap_local_page() doesn't. Converting the former to the latter is safe
> only if there isn't an implicit dependency on preemption and page-fault
> handling being disabled, which does appear to be the case here.
>
> Also note that the page being mapped is not allocated by the driver, and so
> the driver doesn't know if the page is in normal memory. This is the reason
> kmap_local_page() is used as opposed to page_address().
>
> I don't have hardware, so this change has only been compile tested.
>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
> ---
> drivers/net/ethernet/sun/sunvnet_common.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/sun/sunvnet_common.c
> b/drivers/net/ethernet/sun/sunvnet_common.c index 80fde5f..a6211b9 100644
> --- a/drivers/net/ethernet/sun/sunvnet_common.c
> +++ b/drivers/net/ethernet/sun/sunvnet_common.c
> @@ -1085,13 +1085,13 @@ static inline int vnet_skb_map(struct ldc_channel
*lp,
> struct sk_buff *skb, u8 *vaddr;
>
> if (nc < ncookies) {
> - vaddr = kmap_atomic(skb_frag_page(f));
> + vaddr = kmap_local_page(skb_frag_page(f));
> blen = skb_frag_size(f);
> blen += 8 - (blen & 7);
> err = ldc_map_single(lp, vaddr +
skb_frag_off(f),
> blen, cookies + nc,
ncookies - nc,
> map_perm);
> - kunmap_atomic(vaddr);
> + kunmap_local(vaddr);
> } else {
> err = -EMSGSIZE;
> }
> --
> 2.37.2
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Thanks,
Fabio
next prev parent reply other threads:[~2022-11-18 9:11 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-17 22:25 [PATCH net-next 0/5] Remove uses of kmap_atomic() Anirudh Venkataramanan
2022-11-17 22:25 ` [PATCH net-next 1/5] ch_ktls: Use kmap_local_page() instead " Anirudh Venkataramanan
2022-11-18 8:14 ` Fabio M. De Francesco
2022-11-18 18:27 ` Anirudh Venkataramanan
2022-11-18 20:18 ` Fabio M. De Francesco
2022-11-18 20:38 ` Anirudh Venkataramanan
2022-11-19 1:22 ` Ira Weiny
2022-11-17 22:25 ` [PATCH net-next 2/5] sfc: " Anirudh Venkataramanan
2022-11-18 8:23 ` Fabio M. De Francesco
2022-11-18 17:47 ` Anirudh Venkataramanan
2022-11-18 19:26 ` Fabio M. De Francesco
2022-11-18 20:34 ` Anirudh Venkataramanan
2022-11-19 1:25 ` Ira Weiny
2022-11-17 22:25 ` [PATCH net-next 3/5] cassini: Remove unnecessary use " Anirudh Venkataramanan
2022-11-18 8:35 ` Fabio M. De Francesco
2022-11-18 17:55 ` Anirudh Venkataramanan
2022-11-18 20:30 ` Fabio M. De Francesco
2022-11-17 22:25 ` [PATCH net-next 4/5] cassini: Use kmap_local_page() instead " Anirudh Venkataramanan
2022-11-18 8:53 ` Fabio M. De Francesco
2022-11-17 22:25 ` [PATCH net-next 5/5] sunvnet: " Anirudh Venkataramanan
2022-11-18 9:11 ` Fabio M. De Francesco [this message]
2022-11-18 20:45 ` Fabio M. De Francesco
2022-11-19 0:47 ` Anirudh Venkataramanan
2022-11-22 11:29 ` [PATCH net-next 0/5] Remove uses " Leon Romanovsky
2022-11-22 18:50 ` Jakub Kicinski
2022-11-22 21:06 ` Anirudh Venkataramanan
2022-11-23 7:34 ` Leon Romanovsky
2022-11-23 18:38 ` Anirudh Venkataramanan
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