[gem5-dev] Change in gem5/gem5[develop]: sim: Consistently use ISO prefixes

2021-01-24 Thread Andreas Sandberg (Gerrit) via gem5-dev
Andreas Sandberg has submitted this change. (  
https://gem5-review.googlesource.com/c/public/gem5/+/39579 )


Change subject: sim: Consistently use ISO prefixes
..

sim: Consistently use ISO prefixes

We currently use the traditional SI-like prefixes to represent
binary multipliers in some contexts. This is ambiguous in many cases
since they overload the meaning of the SI prefix.

Here are some examples of commonly used in the industry:
  * Storage vendors define 1 MB as 10**6 bytes
  * Memory vendors define 1 MB as 2**20 bytes
  * Network equipment treats 1Mbit/s as 10**6 bits/s
  * Memory vendors define 1Mbit as 2**20 bits

In practice, this means that a FLASH chip on a storage bus uses
decimal prefixes, but that same flash chip on a memory bus uses binary
prefixes. It would also be reasonable to assume that the contents of a
1Mbit FLASH chip would take 0.1s to transfer over a 10Mbit Ethernet
link. That's however not the case due to different meanings of the
prefix.

The quantity 2MX is treated differently by gem5 depending on the unit
X:

  * Physical quantities (s, Hz, V, A, J, K, C, F) use decimal prefixes.
  * Interconnect and NoC bandwidths (B/s) use binary prefixes.
  * Network bandwidths (bps) use decimal prefixes.
  * Memory sizes and storage sizes (B) use binary prefixes.

Mitigate this ambiguity by consistently using the ISO/IEC/SI prefixes
for binary multipliers for parameters and comments where appropriate.

Change-Id: I797163c8690ae0092e00e371d75f5e7cebbcd1f5
Signed-off-by: Andreas Sandberg 
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39579
Reviewed-by: Jason Lowe-Power 
Tested-by: kokoro 
---
M src/sim/Process.py
M src/sim/syscall_emul.hh
2 files changed, 3 insertions(+), 3 deletions(-)

Approvals:
  Jason Lowe-Power: Looks good to me, approved
  Andreas Sandberg: Looks good to me, approved
  kokoro: Regressions pass



diff --git a/src/sim/Process.py b/src/sim/Process.py
index bdcb826..767dbfa 100644
--- a/src/sim/Process.py
+++ b/src/sim/Process.py
@@ -44,7 +44,7 @@
 useArchPT = Param.Bool('false', 'maintain an in-memory version of the  
page\

 table in an architecture-specific format')
 kvmInSE = Param.Bool('false', 'initialize the process for KvmCPU in  
SE')

-maxStackSize = Param.MemorySize('64MB', 'maximum size of the stack')
+maxStackSize = Param.MemorySize('64MiB', 'maximum size of the stack')

 uid = Param.Int(100, 'user id')
 euid = Param.Int(100, 'effective user id')
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index 581e8db..d6afec8 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -1822,7 +1822,7 @@
 const ByteOrder bo = OS::byteOrder;
 switch (resource) {
   case OS::TGT_RLIMIT_STACK:
-// max stack size in bytes: make up a number (8MB for now)
+// max stack size in bytes: make up a number (8MiB for now)
 rlp->rlim_cur = rlp->rlim_max = 8 * 1024 * 1024;
 rlp->rlim_cur = htog(rlp->rlim_cur, bo);
 rlp->rlim_max = htog(rlp->rlim_max, bo);
@@ -1865,7 +1865,7 @@
 const ByteOrder bo = OS::byteOrder;
 switch (resource) {
   case OS::TGT_RLIMIT_STACK:
-// max stack size in bytes: make up a number (8MB for now)
+// max stack size in bytes: make up a number (8MiB for now)
 rlp->rlim_cur = rlp->rlim_max = 8 * 1024 * 1024;
 rlp->rlim_cur = htog(rlp->rlim_cur, bo);
 rlp->rlim_max = htog(rlp->rlim_max, bo);

--
To view, visit https://gem5-review.googlesource.com/c/public/gem5/+/39579
To unsubscribe, or for help writing mail filters, visit  
https://gem5-review.googlesource.com/settings


Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: I797163c8690ae0092e00e371d75f5e7cebbcd1f5
Gerrit-Change-Number: 39579
Gerrit-PatchSet: 3
Gerrit-Owner: Andreas Sandberg 
Gerrit-Reviewer: Andreas Sandberg 
Gerrit-Reviewer: Daniel Carvalho 
Gerrit-Reviewer: Jason Lowe-Power 
Gerrit-Reviewer: Jason Lowe-Power 
Gerrit-Reviewer: Richard Cooper 
Gerrit-Reviewer: kokoro 
Gerrit-MessageType: merged
___
gem5-dev mailing list -- gem5-dev@gem5.org
To unsubscribe send an email to gem5-dev-le...@gem5.org
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s

[gem5-dev] Change in gem5/gem5[develop]: sim: Consistently use ISO prefixes

2021-01-21 Thread Andreas Sandberg (Gerrit) via gem5-dev
Andreas Sandberg has uploaded this change for review. (  
https://gem5-review.googlesource.com/c/public/gem5/+/39579 )



Change subject: sim: Consistently use ISO prefixes
..

sim: Consistently use ISO prefixes

We currently use the traditional SI-like prefixes for to represent
binary multipliers in some contexts. This is ambiguous in many cases
since they overload the meaning of the SI prefix.

Here are some examples of commonly used in the industry:
  * Storage vendors define 1 MB as 10**6 bytes
  * Memory vendors define 1 MB as 2**20 bytes
  * Network equipment treats 1Mbit/s as 10**6 bits/s
  * Memory vendors define 1Mbit as 2**20 bits

In practice, this means that a FLASH chip on a storage bus uses
decimal prefixes, but that same flash chip on a memory bus uses binary
prefixes. It would also be reasonable to assume that the contents of a
1Mbit FLASH chip would take 0.1s to transfer over a 10Mbit Ethernet
link. That's however not the case due to different meanings of the
prefix.

The quantity 2MX is treated differently by gem5 depending on the unit
X:

  * Physical quantities (s, Hz, V, A, J, K, C, F) use decimal prefixes.
  * Interconnect and NoC bandwidths (B/s) use binary prefixes.
  * Network bandwidths (bps) use decimal prefixes.
  * Memory sizes and storage sizes (B) use binary prefixes.

Mitigate this ambiguity by consistently using the ISO/IEC/SI prefixes
for binary multipliers for parameters and comments where appropriate.

Change-Id: I797163c8690ae0092e00e371d75f5e7cebbcd1f5
Signed-off-by: Andreas Sandberg 
---
M src/sim/Process.py
M src/sim/syscall_emul.hh
2 files changed, 3 insertions(+), 3 deletions(-)



diff --git a/src/sim/Process.py b/src/sim/Process.py
index bdcb826..767dbfa 100644
--- a/src/sim/Process.py
+++ b/src/sim/Process.py
@@ -44,7 +44,7 @@
 useArchPT = Param.Bool('false', 'maintain an in-memory version of the  
page\

 table in an architecture-specific format')
 kvmInSE = Param.Bool('false', 'initialize the process for KvmCPU in  
SE')

-maxStackSize = Param.MemorySize('64MB', 'maximum size of the stack')
+maxStackSize = Param.MemorySize('64MiB', 'maximum size of the stack')

 uid = Param.Int(100, 'user id')
 euid = Param.Int(100, 'effective user id')
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index 79cd35a..16fd175 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -1824,7 +1824,7 @@
 const ByteOrder bo = OS::byteOrder;
 switch (resource) {
   case OS::TGT_RLIMIT_STACK:
-// max stack size in bytes: make up a number (8MB for now)
+// max stack size in bytes: make up a number (8MiB for now)
 rlp->rlim_cur = rlp->rlim_max = 8 * 1024 * 1024;
 rlp->rlim_cur = htog(rlp->rlim_cur, bo);
 rlp->rlim_max = htog(rlp->rlim_max, bo);
@@ -1867,7 +1867,7 @@
 const ByteOrder bo = OS::byteOrder;
 switch (resource) {
   case OS::TGT_RLIMIT_STACK:
-// max stack size in bytes: make up a number (8MB for now)
+// max stack size in bytes: make up a number (8MiB for now)
 rlp->rlim_cur = rlp->rlim_max = 8 * 1024 * 1024;
 rlp->rlim_cur = htog(rlp->rlim_cur, bo);
 rlp->rlim_max = htog(rlp->rlim_max, bo);

--
To view, visit https://gem5-review.googlesource.com/c/public/gem5/+/39579
To unsubscribe, or for help writing mail filters, visit  
https://gem5-review.googlesource.com/settings


Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: I797163c8690ae0092e00e371d75f5e7cebbcd1f5
Gerrit-Change-Number: 39579
Gerrit-PatchSet: 1
Gerrit-Owner: Andreas Sandberg 
Gerrit-MessageType: newchange
___
gem5-dev mailing list -- gem5-dev@gem5.org
To unsubscribe send an email to gem5-dev-le...@gem5.org
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s