* [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation [not found] <1356315256-6572-1-git-send-email-akinobu.mita@gmail.com> @ 2012-12-24 2:14 ` Akinobu Mita 2012-12-25 11:26 ` Antonio Quartulli 2012-12-24 2:14 ` [B.A.T.M.A.N.] [PATCH 20/29] batman-adv: rename random32() to prandom_u32() Akinobu Mita 1 sibling, 1 reply; 7+ messages in thread From: Akinobu Mita @ 2012-12-24 2:14 UTC (permalink / raw) To: linux-kernel, akpm Cc: netdev, b.a.t.m.a.n, Akinobu Mita, Simon Wunderlich, Marek Lindner, David S. Miller batadv_iv_ogm_emit_send_time() attempts to calculates a random integer in the range of 'orig_interval +- BATADV_JITTER' by the below lines. msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; msecs += (random32() % 2 * BATADV_JITTER); But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' because '%' and '*' have same precedence and associativity is left-to-right. This adds the parentheses at the appropriate position so that it matches original intension. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Lindner <lindner_marek@yahoo.de> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> Cc: Antonio Quartulli <ordex@autistici.org> Cc: b.a.t.m.a.n@lists.open-mesh.org Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org --- net/batman-adv/bat_iv_ogm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 9f3925a..7d02ebd 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -123,7 +123,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) unsigned int msecs; msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; - msecs += (random32() % 2 * BATADV_JITTER); + msecs += random32() % (2 * BATADV_JITTER); return jiffies + msecs_to_jiffies(msecs); } -- 1.7.11.7 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation 2012-12-24 2:14 ` [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation Akinobu Mita @ 2012-12-25 11:26 ` Antonio Quartulli 2012-12-25 21:35 ` Akinobu Mita 0 siblings, 1 reply; 7+ messages in thread From: Antonio Quartulli @ 2012-12-25 11:26 UTC (permalink / raw) To: Akinobu Mita Cc: netdev, b.a.t.m.a.n, linux-kernel, Simon Wunderlich, akpm, Marek Lindner, David S. Miller [-- Attachment #1: Type: text/plain, Size: 1159 bytes --] On Mon, Dec 24, 2012 at 11:14:06AM +0900, Akinobu Mita wrote: > batadv_iv_ogm_emit_send_time() attempts to calculates a random integer > in the range of 'orig_interval +- BATADV_JITTER' by the below lines. > > msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; > msecs += (random32() % 2 * BATADV_JITTER); > > But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' > because '%' and '*' have same precedence and associativity is > left-to-right. > > This adds the parentheses at the appropriate position so that it matches > original intension. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Marek Lindner <lindner_marek@yahoo.de> > Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> > Cc: Antonio Quartulli <ordex@autistici.org> > Cc: b.a.t.m.a.n@lists.open-mesh.org > Cc: "David S. Miller" <davem@davemloft.net> > Cc: netdev@vger.kernel.org > --- Acked-by: Antonio Quartulli <ordex@autistici.org> But I would suggest to apply this change to net, since it is a fix. Cheers, -- Antonio Quartulli ..each of us alone is worth nothing.. Ernesto "Che" Guevara [-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation 2012-12-25 11:26 ` Antonio Quartulli @ 2012-12-25 21:35 ` Akinobu Mita 2012-12-25 21:37 ` David Miller 0 siblings, 1 reply; 7+ messages in thread From: Akinobu Mita @ 2012-12-25 21:35 UTC (permalink / raw) To: Antonio Quartulli Cc: netdev, b.a.t.m.a.n, linux-kernel, Simon Wunderlich, akpm, Marek Lindner, David S. Miller 2012/12/25 Antonio Quartulli <ordex@autistici.org>: > On Mon, Dec 24, 2012 at 11:14:06AM +0900, Akinobu Mita wrote: >> batadv_iv_ogm_emit_send_time() attempts to calculates a random integer >> in the range of 'orig_interval +- BATADV_JITTER' by the below lines. >> >> msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; >> msecs += (random32() % 2 * BATADV_JITTER); >> >> But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' >> because '%' and '*' have same precedence and associativity is >> left-to-right. >> >> This adds the parentheses at the appropriate position so that it matches >> original intension. >> >> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> >> Cc: Marek Lindner <lindner_marek@yahoo.de> >> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> >> Cc: Antonio Quartulli <ordex@autistici.org> >> Cc: b.a.t.m.a.n@lists.open-mesh.org >> Cc: "David S. Miller" <davem@davemloft.net> >> Cc: netdev@vger.kernel.org >> --- > > Acked-by: Antonio Quartulli <ordex@autistici.org> > > But I would suggest to apply this change to net, since it is a fix. I agree. David, please consider to apply this patch for 3.8-rc*. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation 2012-12-25 21:35 ` Akinobu Mita @ 2012-12-25 21:37 ` David Miller 0 siblings, 0 replies; 7+ messages in thread From: David Miller @ 2012-12-25 21:37 UTC (permalink / raw) To: akinobu.mita; +Cc: netdev, b.a.t.m.a.n, linux-kernel, siwu, akpm, lindner_marek From: Akinobu Mita <akinobu.mita@gmail.com> Date: Wed, 26 Dec 2012 06:35:37 +0900 > 2012/12/25 Antonio Quartulli <ordex@autistici.org>: >> On Mon, Dec 24, 2012 at 11:14:06AM +0900, Akinobu Mita wrote: >>> batadv_iv_ogm_emit_send_time() attempts to calculates a random integer >>> in the range of 'orig_interval +- BATADV_JITTER' by the below lines. >>> >>> msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; >>> msecs += (random32() % 2 * BATADV_JITTER); >>> >>> But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' >>> because '%' and '*' have same precedence and associativity is >>> left-to-right. >>> >>> This adds the parentheses at the appropriate position so that it matches >>> original intension. >>> >>> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> >>> Cc: Marek Lindner <lindner_marek@yahoo.de> >>> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> >>> Cc: Antonio Quartulli <ordex@autistici.org> >>> Cc: b.a.t.m.a.n@lists.open-mesh.org >>> Cc: "David S. Miller" <davem@davemloft.net> >>> Cc: netdev@vger.kernel.org >>> --- >> >> Acked-by: Antonio Quartulli <ordex@autistici.org> >> >> But I would suggest to apply this change to net, since it is a fix. > > I agree. > David, please consider to apply this patch for 3.8-rc*. > All patches I should consider seriously should be properly reposted for review and inclusion. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [B.A.T.M.A.N.] [PATCH 20/29] batman-adv: rename random32() to prandom_u32() [not found] <1356315256-6572-1-git-send-email-akinobu.mita@gmail.com> 2012-12-24 2:14 ` [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation Akinobu Mita @ 2012-12-24 2:14 ` Akinobu Mita 2012-12-25 11:30 ` Antonio Quartulli 1 sibling, 1 reply; 7+ messages in thread From: Akinobu Mita @ 2012-12-24 2:14 UTC (permalink / raw) To: linux-kernel, akpm Cc: netdev, b.a.t.m.a.n, Akinobu Mita, Simon Wunderlich, Marek Lindner, David S. Miller Use more preferable function name which implies using a pseudo-random number generator. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Lindner <lindner_marek@yahoo.de> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> Cc: Antonio Quartulli <ordex@autistici.org> Cc: b.a.t.m.a.n@lists.open-mesh.org Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org --- net/batman-adv/bat_iv_ogm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 7d02ebd..bc434c4 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -123,7 +123,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) unsigned int msecs; msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; - msecs += random32() % (2 * BATADV_JITTER); + msecs += prandom_u32() % (2 * BATADV_JITTER); return jiffies + msecs_to_jiffies(msecs); } @@ -131,7 +131,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) /* when do we schedule a ogm packet to be sent */ static unsigned long batadv_iv_ogm_fwd_send_time(void) { - return jiffies + msecs_to_jiffies(random32() % (BATADV_JITTER / 2)); + return jiffies + msecs_to_jiffies(prandom_u32() % (BATADV_JITTER / 2)); } /* apply hop penalty for a normal link */ -- 1.7.11.7 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCH 20/29] batman-adv: rename random32() to prandom_u32() 2012-12-24 2:14 ` [B.A.T.M.A.N.] [PATCH 20/29] batman-adv: rename random32() to prandom_u32() Akinobu Mita @ 2012-12-25 11:30 ` Antonio Quartulli 2013-01-02 11:52 ` Marek Lindner 0 siblings, 1 reply; 7+ messages in thread From: Antonio Quartulli @ 2012-12-25 11:30 UTC (permalink / raw) To: Akinobu Mita Cc: netdev, b.a.t.m.a.n, linux-kernel, Simon Wunderlich, akpm, Marek Lindner, David S. Miller [-- Attachment #1: Type: text/plain, Size: 619 bytes --] On Mon, Dec 24, 2012 at 11:14:07AM +0900, Akinobu Mita wrote: > Use more preferable function name which implies using a pseudo-random > number generator. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Marek Lindner <lindner_marek@yahoo.de> > Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> > Cc: Antonio Quartulli <ordex@autistici.org> > Cc: b.a.t.m.a.n@lists.open-mesh.org > Cc: "David S. Miller" <davem@davemloft.net> > Cc: netdev@vger.kernel.org Acked-by: Antonio Quartulli <ordex@autistici.org> -- Antonio Quartulli ..each of us alone is worth nothing.. Ernesto "Che" Guevara [-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCH 20/29] batman-adv: rename random32() to prandom_u32() 2012-12-25 11:30 ` Antonio Quartulli @ 2013-01-02 11:52 ` Marek Lindner 0 siblings, 0 replies; 7+ messages in thread From: Marek Lindner @ 2013-01-02 11:52 UTC (permalink / raw) To: b.a.t.m.a.n Cc: netdev, Akinobu Mita, Simon Wunderlich, linux-kernel, akpm, David S. Miller On Tuesday, December 25, 2012 19:30:36 Antonio Quartulli wrote: > On Mon, Dec 24, 2012 at 11:14:07AM +0900, Akinobu Mita wrote: > > Use more preferable function name which implies using a pseudo-random > > number generator. > > > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > > Cc: Marek Lindner <lindner_marek@yahoo.de> > > Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> > > Cc: Antonio Quartulli <ordex@autistici.org> > > Cc: b.a.t.m.a.n@lists.open-mesh.org > > Cc: "David S. Miller" <davem@davemloft.net> > > Cc: netdev@vger.kernel.org > > Acked-by: Antonio Quartulli <ordex@autistici.org> Applied in revision 02c5591. Thanks, Marek ^ permalink raw reply [flat|nested] 7+ messages in thread
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2012-12-24 2:14 ` [B.A.T.M.A.N.] [PATCH 19/29] batman-adv: fix random jitter calculation Akinobu Mita
2012-12-25 11:26 ` Antonio Quartulli
2012-12-25 21:35 ` Akinobu Mita
2012-12-25 21:37 ` David Miller
2012-12-24 2:14 ` [B.A.T.M.A.N.] [PATCH 20/29] batman-adv: rename random32() to prandom_u32() Akinobu Mita
2012-12-25 11:30 ` Antonio Quartulli
2013-01-02 11:52 ` Marek Lindner
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