On Sat, Oct 10, 2020 at 08:53:00AM -0700, Elena Afanasova wrote: > On Sat, 2020-10-10 at 17:07 +1100, David Gibson wrote: > > On Fri, Oct 09, 2020 at 07:02:56AM -0700, Elena Afanasova wrote: > > > > From 09905773a00e417d3a37c12350d9e55466fdce8a Mon Sep 17 00:00:00 > > > > 2001 > > > From: Elena Afanasova <eafanas...@gmail.com> > > > Date: Fri, 9 Oct 2020 06:41:36 -0700 > > > Subject: [PATCH] hw/net: move allocation to the heap due to very > > > large stack > > > frame > > > > Patch looks fine, but some more details of the motivation would be > > nice. I wouldn't have thought that the size of a network packet > > counted as a "very large" stack frame by userspace standards. > > > > gcc with wstack-usage warns that stack frame size may be ~65Kbytes
AFAICT, -Wstack-usage takes a parameter giving what size it will
complain about. What was that value, and what was the rationale for
choosing it?
>
> > > Signed-off-by: Elena Afanasova <eafanas...@gmail.com>
> > > ---
> > > hw/net/spapr_llan.c | 5 +++--
> > > 1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/hw/net/spapr_llan.c b/hw/net/spapr_llan.c
> > > index 2093f1bad0..581320a0e7 100644
> > > --- a/hw/net/spapr_llan.c
> > > +++ b/hw/net/spapr_llan.c
> > > @@ -688,7 +688,8 @@ static target_ulong
> > > h_send_logical_lan(PowerPCCPU *cpu,
> > > SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus,
> > > reg);
> > > SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
> > > unsigned total_len;
> > > - uint8_t *lbuf, *p;
> > > + uint8_t *p;
> > > + g_autofree uint8_t *lbuf = NULL;
> > > int i, nbufs;
> > > int ret;
> > >
> > > @@ -729,7 +730,7 @@ static target_ulong
> > > h_send_logical_lan(PowerPCCPU *cpu,
> > > return H_RESOURCE;
> > > }
> > >
> > > - lbuf = alloca(total_len);
> > > + lbuf = g_malloc(total_len);
> > > p = lbuf;
> > > for (i = 0; i < nbufs; i++) {
> > > ret = spapr_vio_dma_read(sdev, VLAN_BD_ADDR(bufs[i]),
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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