ipc: HARD_MSGMAX should be higher not lower on 64bit
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From: Serge E. Hallyn on 11 Dec 2009 09:50 Quoting Amerigo Wang (amwang(a)redhat.com): > It looks weird that we have HARD_MSGMAX lower on 64bit than on 32bit, > since usually 64bit machines have more memory than 32bit machines. It does look like this may have been an accident. > Making it higher on 64bit seems reasonable, and keep the original > number on 32bit. > > Cc: Serge E. Hallyn <serue(a)us.ibm.com> > Cc: Cedric Le Goater <clg(a)fr.ibm.com> > Signed-off-by: WANG Cong <amwang(a)redhat.com> > > --- > diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h > index e408722..07baa38 100644 > --- a/include/linux/ipc_namespace.h > +++ b/include/linux/ipc_namespace.h > @@ -87,7 +87,7 @@ extern int mq_init_ns(struct ipc_namespace *ns); > /* default values */ > #define DFLT_QUEUESMAX 256 /* max number of message queues */ > #define DFLT_MSGMAX 10 /* max number of messages in each queue */ > -#define HARD_MSGMAX (131072/sizeof(void *)) > +#define HARD_MSGMAX (32768*sizeof(void *)/4) why /4 ? You're now making it much smaller for 32-bit than it used to be? > #define DFLT_MSGSIZEMAX 8192 /* max message size */ > #else > static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Américo Wang on 11 Dec 2009 10:30 (Hi, I am the same person.) On Fri, Dec 11, 2009 at 08:44:33AM -0600, Serge E. Hallyn wrote: >Quoting Amerigo Wang (amwang(a)redhat.com): >> It looks weird that we have HARD_MSGMAX lower on 64bit than on 32bit, >> since usually 64bit machines have more memory than 32bit machines. > >It does look like this may have been an accident. > OK. >> Making it higher on 64bit seems reasonable, and keep the original >> number on 32bit. >> >> Cc: Serge E. Hallyn <serue(a)us.ibm.com> >> Cc: Cedric Le Goater <clg(a)fr.ibm.com> >> Signed-off-by: WANG Cong <amwang(a)redhat.com> >> >> --- >> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h >> index e408722..07baa38 100644 >> --- a/include/linux/ipc_namespace.h >> +++ b/include/linux/ipc_namespace.h >> @@ -87,7 +87,7 @@ extern int mq_init_ns(struct ipc_namespace *ns); >> /* default values */ >> #define DFLT_QUEUESMAX 256 /* max number of message queues */ >> #define DFLT_MSGMAX 10 /* max number of messages in each queue */ >> -#define HARD_MSGMAX (131072/sizeof(void *)) >> +#define HARD_MSGMAX (32768*sizeof(void *)/4) > >why /4 ? You're now making it much smaller for 32-bit than it >used to be? > Yes? Before this patch, it is 131072/sizeof(void*) = 32768; after this patch, it is 32768*sizeof(void*)/4 = 32768 too. Both on 32bit, of course. Am I missing something? -- Live like a child, think like the god. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Serge E. Hallyn on 11 Dec 2009 11:20
Quoting Am�rico Wang (xiyou.wangcong(a)gmail.com): > > (Hi, I am the same person.) > > On Fri, Dec 11, 2009 at 08:44:33AM -0600, Serge E. Hallyn wrote: > >Quoting Amerigo Wang (amwang(a)redhat.com): > >> It looks weird that we have HARD_MSGMAX lower on 64bit than on 32bit, > >> since usually 64bit machines have more memory than 32bit machines. > > > >It does look like this may have been an accident. > > > > OK. > > >> Making it higher on 64bit seems reasonable, and keep the original > >> number on 32bit. > >> > >> Cc: Serge E. Hallyn <serue(a)us.ibm.com> > >> Cc: Cedric Le Goater <clg(a)fr.ibm.com> > >> Signed-off-by: WANG Cong <amwang(a)redhat.com> > >> > >> --- > >> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h > >> index e408722..07baa38 100644 > >> --- a/include/linux/ipc_namespace.h > >> +++ b/include/linux/ipc_namespace.h > >> @@ -87,7 +87,7 @@ extern int mq_init_ns(struct ipc_namespace *ns); > >> /* default values */ > >> #define DFLT_QUEUESMAX 256 /* max number of message queues */ > >> #define DFLT_MSGMAX 10 /* max number of messages in each queue */ > >> -#define HARD_MSGMAX (131072/sizeof(void *)) > >> +#define HARD_MSGMAX (32768*sizeof(void *)/4) > > > >why /4 ? You're now making it much smaller for 32-bit than it > >used to be? > > > > Yes? > > Before this patch, it is 131072/sizeof(void*) = 32768; > after this patch, it is 32768*sizeof(void*)/4 = 32768 too. > Both on 32bit, of course. > > Am I missing something? Haha, nope. Acked-by: Serge Hallyn <serue(a)us.ibm.com> thanks, -serge -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |