Re: [dpdk-dev] [PATCH] replaced O(n^2) sort in sort_by_physaddr() with qsort() from standard library

[Jay Rolette <rolette@infiniteio.com>]

Thanks Konstantin. Yes, I'll resend. Not sure why gmail is removing
whitespace when I sent in Plain Text mode.

Ultimately I'll need to figure out how to properly configure git to send
these directly instead of handling them more manually. The examples I saw
assumed you were using a gmail.com email rather than a corporate email
hosted via google apps.

Jay

On Tue, Dec 16, 2014 at 12:39 PM, Ananyev, Konstantin <
konstantin.ananyev@intel.com> wrote:
>
>
> Hi Jay,
>
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jay Rolette
> > Sent: Thursday, December 11, 2014 4:06 PM
> > To: Dev
> > Subject: [dpdk-dev] [PATCH] replaced O(n^2) sort in sort_by_physaddr()
> with qsort() from standard library
> >
> > Signed-off-by: Jay Rolette <rolette@infiniteio.com>
>
> The patch itself looks good to me.
> Though it seems something wrong with formatting - all lines start with
> offset 0.
> Probably your mail client?
> Konstantin
>
>
> > ---
> >  lib/librte_eal/linuxapp/eal/eal_memory.c | 59
> > +++++++++++---------------------
> >  1 file changed, 20 insertions(+), 39 deletions(-)
> >
> > diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c
> > b/lib/librte_eal/linuxapp/eal/eal_memory.c
> > index bae2507..3656515 100644
> > --- a/lib/librte_eal/linuxapp/eal/eal_memory.c
> > +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
> > @@ -670,6 +670,25 @@ error:
> >   return -1;
> >  }
> >
> > +static int
> > +cmp_physaddr(const void *a, const void *b)
> > +{
> > +#ifndef RTE_ARCH_PPC_64
> > + const struct hugepage_file *p1 = (const struct hugepage_file *)a;
> > + const struct hugepage_file *p2 = (const struct hugepage_file *)b;
> > +#else
> > + // PowerPC needs memory sorted in reverse order from x86
> > + const struct hugepage_file *p1 = (const struct hugepage_file *)b;
> > + const struct hugepage_file *p2 = (const struct hugepage_file *)a;
> > +#endif
> > + if (p1->physaddr < p2->physaddr)
> > + return -1;
> > + else if (p1->physaddr > p2->physaddr)
> > + return 1;
> > + else
> > + return 0;
> > +}
> > +
> >  /*
> >   * Sort the hugepg_tbl by physical address (lower addresses first on
> x86,
> >   * higher address first on powerpc). We use a slow algorithm, but we
> won't
> > @@ -678,45 +697,7 @@ error:
> >  static int
> >  sort_by_physaddr(struct hugepage_file *hugepg_tbl, struct hugepage_info
> > *hpi)
> >  {
> > - unsigned i, j;
> > - int compare_idx;
> > - uint64_t compare_addr;
> > - struct hugepage_file tmp;
> > -
> > - for (i = 0; i < hpi->num_pages[0]; i++) {
> > - compare_addr = 0;
> > - compare_idx = -1;
> > -
> > - /*
> > - * browse all entries starting at 'i', and find the
> > - * entry with the smallest addr
> > - */
> > - for (j=i; j< hpi->num_pages[0]; j++) {
> > -
> > - if (compare_addr == 0 ||
> > -#ifdef RTE_ARCH_PPC_64
> > - hugepg_tbl[j].physaddr > compare_addr) {
> > -#else
> > - hugepg_tbl[j].physaddr < compare_addr) {
> > -#endif
> > - compare_addr = hugepg_tbl[j].physaddr;
> > - compare_idx = j;
> > - }
> > - }
> > -
> > - /* should not happen */
> > - if (compare_idx == -1) {
> > - RTE_LOG(ERR, EAL, "%s(): error in physaddr sorting\n", __func__);
> > - return -1;
> > - }
> > -
> > - /* swap the 2 entries in the table */
> > - memcpy(&tmp, &hugepg_tbl[compare_idx],
> > - sizeof(struct hugepage_file));
> > - memcpy(&hugepg_tbl[compare_idx], &hugepg_tbl[i],
> > - sizeof(struct hugepage_file));
> > - memcpy(&hugepg_tbl[i], &tmp, sizeof(struct hugepage_file));
> > - }
> > + qsort(hugepg_tbl, hpi->num_pages[0], sizeof(struct hugepage_file),
> > cmp_physaddr);
> >   return 0;
> >  }
> >
> > --
>