+Eric > -----Original Message----- > From: Yuan, Linyu (NSB - CN/Shanghai) [mailto:linyu.y...@nokia-sbell.com] > > I just saw below accepted commit, it said "per cpu allocations are already > zeroed, no need to clear them again." > > https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=bfd8e5a407133e58a92a38ccf3d0ba6db81f22d8 > > I will not touch memory sub-system, so I will not change this function > description. >
Your particular change removes redundancy, it's fine. Having the memset documented somewhere would prevent similar redundancy from being added in the future. > > -----Original Message----- > > From: Madalin-cristian Bucur [mailto:madalin.bu...@nxp.com] > > Sent: Monday, October 30, 2017 1:56 PM > > To: Yuan, Linyu (NSB - CN/Shanghai); yuan linyu; netdev@vger.kernel.org; > > gre...@linuxfoundation.org > > Cc: David S . Miller > > Subject: RE: [PATCH net-next] net: dpaa: remove init which already done > in > > per-cpu allocation > > > > Also here: > > > > > > http://elixir.free-electrons.com/linux/latest/source/mm/percpu.c#L717 > > > > Should the fact that the memory is zeroed be included in the function > > description? > > > > /** > > * pcpu_alloc - the percpu allocator > > * @size: size of area to allocate in bytes > > * @align: alignment of area (max PAGE_SIZE) > > * @reserved: allocate from the reserved chunk if available > > * @gfp: allocation flags > > * > > * Allocate percpu area of @size bytes aligned at @align. If @gfp > doesn't > > * contain %GFP_KERNEL, the allocation is atomic. > > * > > * RETURNS: > > * Percpu pointer to the allocated area on success, NULL on failure. > > */ > > > > Now it seems to be an implementation detail rather than a guarantee. > > > > Looking at Documentation/driver-model/devres.txt, the memset is not > > mentioned there either. > > > > > -----Original Message----- > > > From: Yuan, Linyu (NSB - CN/Shanghai) [mailto:linyu.yuan@nokia- > sbell.com] > > > Sent: Monday, October 30, 2017 7:21 AM > > > To: Madalin-cristian Bucur <madalin.bu...@nxp.com>; yuan linyu > > > <cug...@163.com>; netdev@vger.kernel.org > > > Cc: David S . Miller <da...@davemloft.net> > > > Subject: RE: [PATCH net-next] net: dpaa: remove init which already > > > done in per-cpu allocation > > > > > > http://elixir.free-electrons.com/linux/latest/source/mm/percpu.c#L1018 > > > > > > > -----Original Message----- > > > > From: Madalin-cristian Bucur [mailto:madalin.bu...@nxp.com] > > > > Sent: Monday, October 30, 2017 1:15 PM > > > > To: Yuan, Linyu (NSB - CN/Shanghai); yuan linyu; > netdev@vger.kernel.org > > > > Cc: David S . Miller > > > > Subject: RE: [PATCH net-next] net: dpaa: remove init which already > > > > done in per-cpu allocation > > > > > > > > Is the memset part documented? > > > > Can you point to the specific comment & code that does it? > > > > > > > > Thanks > > > > > > > > > -----Original Message----- > > > > > From: Yuan, Linyu (NSB - CN/Shanghai) [mailto:linyu.yuan@nokia- > > > sbell.com] > > > > > Sent: Monday, October 30, 2017 7:12 AM > > > > > To: Madalin-cristian Bucur <madalin.bu...@nxp.com>; yuan linyu > > > > > <cug...@163.com>; netdev@vger.kernel.org > > > > > Cc: David S . Miller <da...@davemloft.net> > > > > > Subject: RE: [PATCH net-next] net: dpaa: remove init which already > > > done in > > > > > per-cpu allocation > > > > > > > > > > Hi, > > > > > > > > > > devm_alloc_percpu() will allocate per-cpu memory and memset > allocated > > > > > block content to 0. > > > > > > > > > > > -----Original Message----- > > > > > > From: Madalin-cristian Bucur [mailto:madalin.bu...@nxp.com] > > > > > > Sent: Monday, October 30, 2017 1:08 PM > > > > > > To: yuan linyu; netdev@vger.kernel.org > > > > > > Cc: David S . Miller; Yuan, Linyu (NSB - CN/Shanghai) > > > > > > Subject: RE: [PATCH net-next] net: dpaa: remove init which > > > > > > already done in per-cpu allocation > > > > > > > > > > > > Hi Yuan, > > > > > > > > > > > > Can you please give more details about this change you are > > > proposing? > > > > > > > > > > > > Regards, > > > > > > Madalin > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: netdev-ow...@vger.kernel.org > > > > > > [mailto:netdev-ow...@vger.kernel.org] > > > > > > > On Behalf Of yuan linyu > > > > > > > Sent: Sunday, October 29, 2017 3:49 AM > > > > > > > To: netdev@vger.kernel.org > > > > > > > Cc: David S . Miller <da...@davemloft.net>; yuan linyu > > > > > > > <linyu.y...@alcatel-sbell.com.cn> > > > > > > > Subject: [PATCH net-next] net: dpaa: remove init which already > > > done in > > > > > > > per-cpu allocation > > > > > > > > > > > > > > From: yuan linyu <linyu.y...@alcatel-sbell.com.cn> > > > > > > > > > > > > > > Signed-off-by: yuan linyu <linyu.y...@alcatel-sbell.com.cn> > > > > > > > --- > > > > > > > drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 4 ---- > > > > > > > 1 file changed, 4 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > > > > > > > b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > > > > > > > index a8d0be8..1ccc316 100644 > > > > > > > --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > > > > > > > +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > > > > > > > @@ -2814,10 +2814,6 @@ static int dpaa_eth_probe(struct > > > > > > platform_device > > > > > > > *pdev) > > > > > > > err = -ENOMEM; > > > > > > > goto free_dpaa_fqs; > > > > > > > } > > > > > > > - for_each_possible_cpu(i) { > > > > > > > - percpu_priv = per_cpu_ptr(priv->percpu_priv, i); > > > > > > > - memset(percpu_priv, 0, sizeof(*percpu_priv)); > > > > > > > - } > > > > > > > > > > > > > > priv->num_tc = 1; > > > > > > > netif_set_real_num_tx_queues(net_dev, priv->num_tc * > > > > > > > DPAA_TC_TXQ_NUM); > > > > > > > -- > > > > > > > 2.7.4 > > > > > > >
