2018-06-18 15:23:05

by Arnd Bergmann

Subject: [PATCH net-next] nfp: avoid using getnstimeofday64()

getnstimeofday64 is deprecated in favor of the ktime_get() family of
functions. The direct replacement would be ktime_get_real_ts64(),
but I'm picking the basic ktime_get() instead:

- using a ktime_t simplifies the code compared to timespec64
- using monotonic time instead of real time avoids issues caused
by a concurrent settimeofday() or during a leap second adjustment.

Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/net/ethernet/netronome/nfp/flower/main.h | 2 +-
drivers/net/ethernet/netronome/nfp/flower/metadata.c | 12 +++++-------
2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/flower/main.h b/drivers/net/ethernet/netronome/nfp/flower/main.h
index bbe5764d26cb..ef2114d13387 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/main.h
+++ b/drivers/net/ethernet/netronome/nfp/flower/main.h
@@ -73,7 +73,7 @@ struct nfp_app;

struct nfp_fl_mask_id {
struct circ_buf mask_id_free_list;
- struct timespec64 *last_used;
+ ktime_t *last_used;
u8 init_unallocated;
};

diff --git a/drivers/net/ethernet/netronome/nfp/flower/metadata.c b/drivers/net/ethernet/netronome/nfp/flower/metadata.c
index 93fb809f50d1..c098730544b7 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/metadata.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/metadata.c
@@ -158,7 +158,6 @@ static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id)
{
struct nfp_flower_priv *priv = app->priv;
struct circ_buf *ring;
- struct timespec64 now;

ring = &priv->mask_ids.mask_id_free_list;
/* Checking if buffer is full. */
@@ -169,8 +168,7 @@ static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id)
ring->head = (ring->head + NFP_FLOWER_MASK_ELEMENT_RS) %
(NFP_FLOWER_MASK_ENTRY_RS * NFP_FLOWER_MASK_ELEMENT_RS);

- getnstimeofday64(&now);
- priv->mask_ids.last_used[mask_id] = now;
+ priv->mask_ids.last_used[mask_id] = ktime_get();

return 0;
}
@@ -178,7 +176,7 @@ static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id)
static int nfp_mask_alloc(struct nfp_app *app, u8 *mask_id)
{
struct nfp_flower_priv *priv = app->priv;
- struct timespec64 delta, now;
+ ktime_t reuse_timeout;
struct circ_buf *ring;
u8 temp_id, freed_id;

@@ -198,10 +196,10 @@ static int nfp_mask_alloc(struct nfp_app *app, u8 *mask_id)
memcpy(&temp_id, &ring->buf[ring->tail], NFP_FLOWER_MASK_ELEMENT_RS);
*mask_id = temp_id;

- getnstimeofday64(&now);
- delta = timespec64_sub(now, priv->mask_ids.last_used[*mask_id]);
+ reuse_timeout = ktime_add_ns(priv->mask_ids.last_used[*mask_id],
+ NFP_FL_MASK_REUSE_TIME_NS);

- if (timespec64_to_ns(&delta) < NFP_FL_MASK_REUSE_TIME_NS)
+ if (ktime_before(ktime_get(), reuse_timeout))
goto err_not_found;

memcpy(&ring->buf[ring->tail], &freed_id, NFP_FLOWER_MASK_ELEMENT_RS);
--
2.9.0

2018-06-18 20:32:50

by Jakub Kicinski

Subject: Re: [PATCH net-next] nfp: avoid using getnstimeofday64()

On Mon, 18 Jun 2018 17:20:17 +0200, Arnd Bergmann wrote:
> getnstimeofday64 is deprecated in favor of the ktime_get() family of
> functions. The direct replacement would be ktime_get_real_ts64(),
> but I'm picking the basic ktime_get() instead:
>
> - using a ktime_t simplifies the code compared to timespec64
> - using monotonic time instead of real time avoids issues caused
> by a concurrent settimeofday() or during a leap second adjustment.
>
> Signed-off-by: Arnd Bergmann <[email protected]>

Acked-by: Jakub Kicinski <[email protected]>

Thank you!