Hi All, Please help me with review Thanks Athira Rajeev
> On 24-Aug-2017, at 12:45 PM, Athira Rajeev <atraj...@linux.vnet.ibm.com> > wrote: > > From: Athira Rajeev <atraj...@linux.vnet.ibm.com > <mailto:atraj...@linux.vnet.ibm.com>> > > testchecksum fails with "verify: isisd failed" for few iterations. > Checking the test code, it calls iso_csum_create followed by verify function > where it fails in some cases. > > Code snippet: > > isisd = iso_csum_create (buffer, exercise + sizeof(u_int16_t), exercise); > if (verify (buffer, exercise + sizeof(u_int16_t))) > printf ("verify: isisd failed\n"); > > In iso_csum_create , code uses modulo ( % ) operation. > Code snippet: > ======== > mul = (init_len - off) * c0; > > x = mul - c1 - c0; > y = c1 - mul - 1; > > if (y > 0) > y++; > if (x < 0) > x--; > > x %= 255; > y %= 255; > > if (x == 0) > x = 255; > if (y == 0) > y = 1; > ======== > > Moved the modulus operation up the if condition in testcase and > isisd verify goes fine without reporting fail. > Referring this mail thread https://lists.gt.net/quagga/dev/17347 > <https://lists.gt.net/quagga/dev/17347> > and > https://github.com/Quagga/quagga/commit/5d4b8cf2faba9f5386810a7c70837e5b7fae3572#diff-5fb4cfc11e8bb396af1ce29581abfb89 > > <https://github.com/Quagga/quagga/commit/5d4b8cf2faba9f5386810a7c70837e5b7fae3572#diff-5fb4cfc11e8bb396af1ce29581abfb89> > , > mod operation was moved up for "reduce_isisd_mod" in past commits. > > Also observed that without moving mod up and introducing sleep after mod > operation also solves the issue : > > --- test-checksum.c.org <http://test-checksum.c.org/> 2017-08-23 > 12:19:43.688263168 +0000 > +++ test-checksum.c 2017-08-23 12:22:43.400260726 +0000 > @@ -360,6 +360,8 @@ iso_csum_create (u_char * buffer, testsz > x %= 255; > y %= 255; > > + sleep(1); > + > if (x == 0) > x = 255; > if (y == 0) > > Reason behind this appears that modulus operator is slow. > Reference links: > https://stackoverflow.com/questions/27977834/why-is-modulus-operator-slow > <https://stackoverflow.com/questions/27977834/why-is-modulus-operator-slow> > > But Since "Moving the mod up" was followed as solution in past commits, > adding that patch here. > > Signed-off-by: Athira Rajeev <atraj...@linux.vnet.ibm.com > <mailto:atraj...@linux.vnet.ibm.com>> > --- > tests/test-checksum.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/tests/test-checksum.c b/tests/test-checksum.c > index b6741f30..99d255ef 100644 > --- a/tests/test-checksum.c > +++ b/tests/test-checksum.c > @@ -352,14 +352,14 @@ iso_csum_create (u_char * buffer, testsz_t len, > testoff_t off) > x = mul - c1 - c0; > y = c1 - mul - 1; > > + x %= 255; > + y %= 255; > + > if (y > 0) > y++; > if (x < 0) > x--; > > - x %= 255; > - y %= 255; > - > if (x == 0) > x = 255; > if (y == 0) > -- > 2.11.0 (Apple Git-81) > _______________________________________________ > Quagga-dev mailing list > Quagga-dev@lists.quagga.net > https://lists.quagga.net/mailman/listinfo/quagga-dev
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