[PATCH 1/3] tools/memory-model/Documentation: Fix typos in explanation.txt

[PATCH 1/3] tools/memory-model/Documentation: Fix typos in explanation.txt

[Alan Stern]

This patch fixes a few minor typos and improves word usage in a few
places in the Linux Kernel Memory Model's explanation.txt file.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>

---

 tools/memory-model/Documentation/explanation.txt |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Index: usb-devel/tools/memory-model/Documentation/explanation.txt
===================================================================
--- usb-devel.orig/tools/memory-model/Documentation/explanation.txt
+++ usb-devel/tools/memory-model/Documentation/explanation.txt
@@ -206,7 +206,7 @@ goes like this:
 	P0 stores 1 to buf before storing 1 to flag, since it executes
 	its instructions in order.
 
-	Since an instruction (in this case, P1's store to flag) cannot
+	Since an instruction (in this case, P0's store to flag) cannot
 	execute before itself, the specified outcome is impossible.
 
 However, real computer hardware almost never follows the Sequential
@@ -419,7 +419,7 @@ example:
 
 The object code might call f(5) either before or after g(6); the
 memory model cannot assume there is a fixed program order relation
-between them.  (In fact, if the functions are inlined then the
+between them.  (In fact, if the function calls are inlined then the
 compiler might even interleave their object code.)
 
 
@@ -499,7 +499,7 @@ different CPUs (external reads-from, or
 
 For our purposes, a memory location's initial value is treated as
 though it had been written there by an imaginary initial store that
-executes on a separate CPU before the program runs.
+executes on a separate CPU before the main program runs.
 
 Usage of the rf relation implicitly assumes that loads will always
 read from a single store.  It doesn't apply properly in the presence
@@ -955,7 +955,7 @@ atomic update.  This is what the LKMM's
 THE PRESERVED PROGRAM ORDER RELATION: ppo
 -----------------------------------------
 
-There are many situations where a CPU is obligated to execute two
+There are many situations where a CPU is obliged to execute two
 instructions in program order.  We amalgamate them into the ppo (for
 "preserved program order") relation, which links the po-earlier
 instruction to the po-later instruction and is thus a sub-relation of
@@ -1572,7 +1572,7 @@ and there are events X, Y and a read-sid
 
 	2. X comes "before" Y in some sense (including rfe, co and fr);
 
-	2. Y is po-before Z;
+	3. Y is po-before Z;
 
 	4. Z is the rcu_read_unlock() event marking the end of C;
 

Re: [PATCH 1/3] tools/memory-model/Documentation: Fix typos in explanation.txt

[Joel Fernandes]

On Tue, Oct 01, 2019 at 01:39:47PM -0400, Alan Stern wrote:
> This patch fixes a few minor typos and improves word usage in a few
> places in the Linux Kernel Memory Model's explanation.txt file.
> 
> Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> 

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>

thanks,

 - Joel


> ---
> 
>  tools/memory-model/Documentation/explanation.txt |   10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> Index: usb-devel/tools/memory-model/Documentation/explanation.txt
> ===================================================================
> --- usb-devel.orig/tools/memory-model/Documentation/explanation.txt
> +++ usb-devel/tools/memory-model/Documentation/explanation.txt
> @@ -206,7 +206,7 @@ goes like this:
>  	P0 stores 1 to buf before storing 1 to flag, since it executes
>  	its instructions in order.
>  
> -	Since an instruction (in this case, P1's store to flag) cannot
> +	Since an instruction (in this case, P0's store to flag) cannot
>  	execute before itself, the specified outcome is impossible.
>  
>  However, real computer hardware almost never follows the Sequential
> @@ -419,7 +419,7 @@ example:
>  
>  The object code might call f(5) either before or after g(6); the
>  memory model cannot assume there is a fixed program order relation
> -between them.  (In fact, if the functions are inlined then the
> +between them.  (In fact, if the function calls are inlined then the
>  compiler might even interleave their object code.)
>  
>  
> @@ -499,7 +499,7 @@ different CPUs (external reads-from, or
>  
>  For our purposes, a memory location's initial value is treated as
>  though it had been written there by an imaginary initial store that
> -executes on a separate CPU before the program runs.
> +executes on a separate CPU before the main program runs.
>  
>  Usage of the rf relation implicitly assumes that loads will always
>  read from a single store.  It doesn't apply properly in the presence
> @@ -955,7 +955,7 @@ atomic update.  This is what the LKMM's
>  THE PRESERVED PROGRAM ORDER RELATION: ppo
>  -----------------------------------------
>  
> -There are many situations where a CPU is obligated to execute two
> +There are many situations where a CPU is obliged to execute two
>  instructions in program order.  We amalgamate them into the ppo (for
>  "preserved program order") relation, which links the po-earlier
>  instruction to the po-later instruction and is thus a sub-relation of
> @@ -1572,7 +1572,7 @@ and there are events X, Y and a read-sid
>  
>  	2. X comes "before" Y in some sense (including rfe, co and fr);
>  
> -	2. Y is po-before Z;
> +	3. Y is po-before Z;
>  
>  	4. Z is the rcu_read_unlock() event marking the end of C;
>  
> 
> 

Re: [PATCH 1/3] tools/memory-model/Documentation: Fix typos in explanation.txt

[Paul E. McKenney]

On Tue, Oct 01, 2019 at 05:01:23PM -0400, Joel Fernandes wrote:
> On Tue, Oct 01, 2019 at 01:39:47PM -0400, Alan Stern wrote:
> > This patch fixes a few minor typos and improves word usage in a few
> > places in the Linux Kernel Memory Model's explanation.txt file.
> > 
> > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > 
> 
> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>

I queued all three for further review, and added Joel's Reviewed-by
to the first one.  Thank you both!

							Thanx, Paul

> thanks,
> 
>  - Joel
> 
> 
> > ---
> > 
> >  tools/memory-model/Documentation/explanation.txt |   10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> > 
> > Index: usb-devel/tools/memory-model/Documentation/explanation.txt
> > ===================================================================
> > --- usb-devel.orig/tools/memory-model/Documentation/explanation.txt
> > +++ usb-devel/tools/memory-model/Documentation/explanation.txt
> > @@ -206,7 +206,7 @@ goes like this:
> >  	P0 stores 1 to buf before storing 1 to flag, since it executes
> >  	its instructions in order.
> >  
> > -	Since an instruction (in this case, P1's store to flag) cannot
> > +	Since an instruction (in this case, P0's store to flag) cannot
> >  	execute before itself, the specified outcome is impossible.
> >  
> >  However, real computer hardware almost never follows the Sequential
> > @@ -419,7 +419,7 @@ example:
> >  
> >  The object code might call f(5) either before or after g(6); the
> >  memory model cannot assume there is a fixed program order relation
> > -between them.  (In fact, if the functions are inlined then the
> > +between them.  (In fact, if the function calls are inlined then the
> >  compiler might even interleave their object code.)
> >  
> >  
> > @@ -499,7 +499,7 @@ different CPUs (external reads-from, or
> >  
> >  For our purposes, a memory location's initial value is treated as
> >  though it had been written there by an imaginary initial store that
> > -executes on a separate CPU before the program runs.
> > +executes on a separate CPU before the main program runs.
> >  
> >  Usage of the rf relation implicitly assumes that loads will always
> >  read from a single store.  It doesn't apply properly in the presence
> > @@ -955,7 +955,7 @@ atomic update.  This is what the LKMM's
> >  THE PRESERVED PROGRAM ORDER RELATION: ppo
> >  -----------------------------------------
> >  
> > -There are many situations where a CPU is obligated to execute two
> > +There are many situations where a CPU is obliged to execute two
> >  instructions in program order.  We amalgamate them into the ppo (for
> >  "preserved program order") relation, which links the po-earlier
> >  instruction to the po-later instruction and is thus a sub-relation of
> > @@ -1572,7 +1572,7 @@ and there are events X, Y and a read-sid
> >  
> >  	2. X comes "before" Y in some sense (including rfe, co and fr);
> >  
> > -	2. Y is po-before Z;
> > +	3. Y is po-before Z;
> >  
> >  	4. Z is the rcu_read_unlock() event marking the end of C;
> >  
> > 
> > 

Re: [PATCH 1/3] tools/memory-model/Documentation: Fix typos in explanation.txt

[Alan Stern]

On Tue, 1 Oct 2019, Joel Fernandes wrote:

> On Tue, Oct 01, 2019 at 01:39:47PM -0400, Alan Stern wrote:
> > This patch fixes a few minor typos and improves word usage in a few
> > places in the Linux Kernel Memory Model's explanation.txt file.
> > 
> > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > 
> 
> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>

Joel, if you're sufficiently interested in all this stuff, would you 
like to add yourself as a maintainer for the LKMM?

Alan

Re: [PATCH 1/3] tools/memory-model/Documentation: Fix typos in explanation.txt

[Joel Fernandes]

On Wed, Oct 02, 2019 at 10:13:43AM -0400, Alan Stern wrote:
> On Tue, 1 Oct 2019, Joel Fernandes wrote:
> 
> > On Tue, Oct 01, 2019 at 01:39:47PM -0400, Alan Stern wrote:
> > > This patch fixes a few minor typos and improves word usage in a few
> > > places in the Linux Kernel Memory Model's explanation.txt file.
> > > 
> > > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > > 
> > 
> > Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> 
> Joel, if you're sufficiently interested in all this stuff, would you 
> like to add yourself as a maintainer for the LKMM?

Absolutely I am quite interested. I will submit a patch for this. Thanks for
the suggestion, Alan!

thanks,

 - Joel