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

[Jay Rolette <rolette@infiniteio.com>]

Actually, I just relooked at the email I sent and it looks correct
(properly indented, etc.). Any suggestions for what might be going on?

On Tue, Dec 16, 2014 at 1:18 PM, Jay Rolette <rolette@infiniteio.com> wrote:
>
> 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;
>> >  }
>> >
>> > --
>>
>