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Hi Kishor,<br>
<br>
<div class="moz-cite-prefix">On 07/20/2017 06:34 PM, Kharbas, Kishor
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:F89640DCD01A85489FCBA68183A6A0F390191140@ORSMSX116.amr.corp.intel.com">
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<div class="WordSection1">
<p class="MsoNormal"><span style="color:#1F497D">I have a new
version of this patch at
<a
href="http://cr.openjdk.java.net/%7Ekkharbas/8171181/webrev.06/"
moz-do-not-send="true">http://cr.openjdk.java.net/~kkharbas/8171181/webrev.06/</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">This version
has been tested on Windows, Linux, Solaris and Mac OS. I
could not get access to AIX for testing.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I used tmpfs to
test the functionality. Cases that were tested were.<o:p></o:p></span></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l1 level1 lfo3"><!--[if !supportLists]--><span
style="color:#1F497D"><span style="mso-list:Ignore">1.<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]--><span
style="color:#1F497D">Allocation of heap using file mapping
when –XX:HeapDir= option is used.<o:p></o:p></span></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l1 level1 lfo3"><!--[if !supportLists]--><span
style="color:#1F497D"><span style="mso-list:Ignore">2.<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]--><span
style="color:#1F497D">Creation of nameless temporary file
for Heap allocation which prevents access to file using its
name.<o:p></o:p></span></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l1 level1 lfo3"><!--[if !supportLists]--><span
style="color:#1F497D"><span style="mso-list:Ignore">3.<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]--><span
style="color:#1F497D">Correct deletion and freeing up of
space allocated for file under different exit conditions.<o:p></o:p></span></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l1 level1 lfo3"><!--[if !supportLists]--><span
style="color:#1F497D"><span style="mso-list:Ignore">4.<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]--><span
style="color:#1F497D">Error handling when path specified is
not present, heap size is more than size of file system,
etc.</span></p>
</div>
</blockquote>
Overall seems good.<br>
I tried to list some missing part.<br>
<br>
1. Please rebase with consolidated repository. (jdk10/hs)<br>
2. Build failure on Solaris.<br>
(Sorry no build error log file, as I tested a few weeks ago, it
is deleted)<br>
3. Have you tested with various heap reserve path using
HeapBaseMinAddress flag? i.e. to test code path of
ReservedHeapSpace::try_reserve_heap() and try_reserve_range().<br>
4. How about adding HeapDir allocation success message? e.g.
gc+heap+coops=info<br>
5. Adding JTREG test. Probably we would need to verify this
allocation is succeeded via #4 added allocation success message.<br>
6. CSR (Compatibility & Specification Review). At some point,
you need to file another CR of 'CSR' type to add a new flag of
'HeapDir'.<br>
7. It will be much appreciated if you provide incremental webrev. I
think 06(this version) vs. 07(rebase version) would be hard to get.
Probably from 08 version.<br>
<br>
Here's my comments.<br>
-----------------------------<br>
src/os/aix/vm/os_aix.cpp<br>
<br>
2514 char* os::pd_attempt_reserve_memory_at(size_t bytes, char*
requested_addr, bool use_SHM) {<br>
- Question. Why os_aix has additional parameter at
pd_attemp_reserve_memory_at()? Probably only AIX has shmated memory
implementation?<br>
<br>
-----------------------------<br>
src/os/posix/vm/os_posix.cpp<br>
<br>
148 char *fullname = (char*)::malloc(strlen(dir) +
sizeof(name_template));<br>
- Use os::malloc()<br>
<br>
196 int flags;<br>
197 <br>
198 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;<br>
- Combining 196 and 198 seems better to me.<br>
<br>
200 assert((uintptr_t)requested_addr % os::Linux::page_size() ==
0, "unaligned address");<br>
- Linux dependency on posix file which makes build error on Solaris.
Probably os::vm_page_size().<br>
<br>
207 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,<br>
208 flags, -1, 0);<br>
- Missing some spaces? Alignment seems odd to me.<br>
<br>
226 if (ret == -1)<br>
- Probably you wanted to add handling code? If not, just return ret.<br>
<br>
252 if (addr == MAP_FAILED || (base != NULL && addr !=
base)) {<br>
253 if (addr != MAP_FAILED) {<br>
254 if (!os::release_memory(addr, size)) {<br>
255 warning("Could not release memory on unsuccessful file
mapping");<br>
256 }<br>
257 }<br>
258 return NULL;<br>
259 }<br>
- Splitting MAP_FAILED case and another gives better readability to
me. But this is your call.<br>
<br>
269 <br>
- Extra line.<br>
<br>
284 if (result != NULL && file_desc != -1) {<br>
285 if (replace_existing_mapping_with_dax_file_mapping(result,
bytes, file_desc) == NULL) {<br>
286 vm_exit_during_initialization(err_msg("Error in mapping
Java heap at the given filesystem directory"));<br>
287 }<br>
288
MemTracker::record_virtual_memory_reserve_and_commit((address)result,
bytes, CALLER_PC);<br>
289 return result;<br>
290 }<br>
291 if (result != NULL) {<br>
292 MemTracker::record_virtual_memory_reserve((address)result,
bytes, CALLER_PC);<br>
293 }<br>
- Combining line 284 and 291 seems better to me.<br>
284 if (result != NULL) {<br>
if (file_desc != -1) {<br>
if (replace_existing_mapping_with_dax_file_mapping(result,
bytes, file_desc) == NULL) {<br>
vm_exit_during_initialization(err_msg("Error in mapping
Java heap at the given filesystem directory"));<br>
}<br>
MemTracker::record_virtual_memory_reserve_and_commit((address)result,
bytes, CALLER_PC);<br>
} else {<br>
MemTracker::record_virtual_memory_reserve((address)result,
bytes, CALLER_PC);<br>
}<br>
}<br>
return result;<br>
<br>
-----------------------------<br>
src/os/windows/vm/os_windows.cpp<br>
3141 // if 'base' is not NULL, function will return NULL if it
cannot get 'base'<br>
- Start with uppercase.<br>
<br>
3142 //<br>
- This line seems redundant.<br>
<br>
3151 vm_exit_during_initialization(err_msg("Could not allocate
sufficient disk space for heap"));<br>
- heap -> Java heap (same as line 3153)<br>
<br>
3168 assert(base != NULL, "base cannot be NULL");<br>
- 'base' -> 'Base' or 'Base address'.<br>
<br>
3172 <br>
- Redundant line.<br>
<br>
3230 }<br>
3231 else {<br>
-> } else {<br>
<br>
3278 return reserve_memory(bytes, requested_addr, 0);<br>
- Is it correct to use '0' not '-1'? It would be better to explain
why we use hard-coded value here.<br>
<br>
-----------------------------<br>
src/share/vm/memory/universe.cpp<br>
- No comments<br>
<br>
-----------------------------<br>
src/share/vm/memory/virtualspace.cpp<br>
- copyright update<br>
<br>
74 const size_t size,
bool special, bool is_file_mapped= false)<br>
- Need space between 'is_file_mapped' and '='.<br>
<br>
92 fatal("os::release_memory failed");<br>
- Typo, 'os::unmap_memory failed'.<br>
<br>
129 // If there is a backing file directory for this VirtualSpace
then whether<br>
- This is not VirtualSpace. Probably just 'space'.<br>
<br>
130 // large pages are allocated is upto the filesystem the dir
resides in.<br>
- 'dir'? Probably 'backing file for Java heap'.<br>
<br>
137 log_debug(gc, heap, coops)("UseLargePages can't be set
with HeapDir option.");<br>
- Is it enough to print log message instead of warning message? i.e.
Don't we need something at arguments.cpp:3656, similar to NUMA
flags?<br>
<br>
191 // unmap_memory will do extra work esp. in Windows<br>
- esp. -> especially<br>
<br>
282 }<br>
283 else {<br>
-> } else {<br>
<br>
346 // If there is a backing file directory for this VirtualSpace
then whether<br>
- Again this is not VirtualSpace, so just 'space'.<br>
<br>
352 if (UseLargePages &&
(!FLAG_IS_DEFAULT(UseLargePages) ||<br>
353 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) {<br>
- Wrong alignment at line 353. Consider to make same as line 380.<br>
<br>
603 ReservedHeapSpace::ReservedHeapSpace(size_t size, size_t
alignment, bool large, const char* backing_fs_for_heap)<br>
- ReservedSpace has '_backing_fd' but the constructor doesn't take
it as a parameter and only ReservedHeapSpace uses it. This seems not
ideal, couldn't make it better? I know actual logic is at
ReservedSpace so it is not convenient to add _backing_fs_for_heap at
ReservedHeapSapce.<br>
<br>
-----------------------------<br>
src/share/vm/memory/virtualspace.hpp<br>
40 int _backing_fd;<br>
- I would prefer to have better name to describe. <br>
e.g. as command-line option name is 'HeapDir', _heap_fd or
_fd_for_heap(similar to below)?<br>
<br>
115 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
bool large, const char* backingFSforHeap = NULL);<br>
- Snake case. How about 'fs_for_heap' or 'heap_fs'?<br>
<br>
-----------------------------<br>
src/share/vm/runtime/arguments.cpp<br>
3655 FLAG_SET_CMDLINE(bool, UseNUMA, false);<br>
- (questions) Don't need to add a warning message for
UseLargePagesSame=true as commented virtualspace.cpp:137?<br>
<br>
-----------------------------<br>
src/share/vm/runtime/globals.hpp<br>
- No comments<br>
<br>
-----------------------------<br>
src/share/vm/runtime/os.cpp<br>
<br>
1632 <br>
- Extra line.<br>
<br>
1642 }<br>
1643 else {<br>
-> } else {<br>
<br>
1663<br>
- You removed os::attempt_reserve_memory_at() from os.cpp and split
into os_posix.cpp and os_windows.cpp.<br>
But I think you should remain os::attempt_reserve_memory_at() at
os.cpp and implement os specific stuffs at each os_xxx.cpp files for
pd_xxx. Of cource move MemTracker function call as well.<br>
<br>
-----------------------------<br>
src/share/vm/runtime/os.hpp<br>
<br>
349 // replace existing reserved memory with file mapping<br>
- Start with uppercase letter.<br>
<br>
Thanks,<br>
Sangheon<br>
<br>
<br>
<blockquote type="cite"
cite="mid:F89640DCD01A85489FCBA68183A6A0F390191140@ORSMSX116.amr.corp.intel.com">
<div class="WordSection1">
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l1 level1 lfo3"><span
style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">- Kishor<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div style="border:none;border-left:solid blue 1.5pt;padding:0in
0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Kharbas, Kishor <br>
<b>Sent:</b> Tuesday, July 11, 2017 6:40 PM<br>
<b>To:</b> '<a class="moz-txt-link-abbreviated" href="mailto:hotspot-gc-dev@openjdk.java.net">hotspot-gc-dev@openjdk.java.net</a>'
<a class="moz-txt-link-rfc2396E" href="mailto:hotspot-gc-dev@openjdk.java.net"><hotspot-gc-dev@openjdk.java.net></a><br>
<b>Cc:</b> Kharbas, Kishor
<a class="moz-txt-link-rfc2396E" href="mailto:kishor.kharbas@intel.com"><kishor.kharbas@intel.com></a><br>
<b>Subject:</b> RFR(M): 8171181: Supporting heap
allocation on alternative memory devices<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Greetings,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I have an
updated patch for JEP <a
href="https://bugs.openjdk.java.net/browse/JDK-8171181"
moz-do-not-send="true">
https://bugs.openjdk.java.net/browse/JDK-8171181</a> at
<a
href="http://cr.openjdk.java.net/%7Ekkharbas/8171181/webrev.05"
moz-do-not-send="true">
http://cr.openjdk.java.net/~kkharbas/8171181/webrev.05</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">This patch
fixes the bugs pointed earlier and other suggestions to
make the code less intrusive.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I have also
sent this to ‘hotspot-runtime-dev’ mailing list (included
below).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I would
appreciate comments and feedback.<o:p></o:p></span></p>
<p class="MsoNormal"><a name="_MailEndCompose"
moz-do-not-send="true"></a><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Kishor<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Kharbas, Kishor <br>
<b>Sent:</b> Monday, July 10, 2017 1:53 PM<br>
<b>To:</b> <a
href="mailto:hotspot-runtime-dev@openjdk.java.net"
moz-do-not-send="true">hotspot-runtime-dev@openjdk.java.net</a><br>
<b>Cc:</b> Kharbas, Kishor <<a
href="mailto:kishor.kharbas@intel.com"
moz-do-not-send="true">kishor.kharbas@intel.com</a>><br>
<b>Subject:</b> RFR(M): 8171181: Supporting heap
allocation on alternative memory devices<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Courier
New";color:black">Hello all!<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<pre>I have an updated patch for <span style="color:black"><a href="https://bugs.openjdk.java.net/browse/JDK-8171181" moz-do-not-send="true">https://bugs.openjdk.java.net/browse/JDK-8171181</a> at <a href="http://cr.openjdk.java.net/%7Ekkharbas/8171181/webrev.05" moz-do-not-send="true">http://cr.openjdk.java.net/~kkharbas/8171181/webrev.05</a><o:p></o:p></span></pre>
<p class="MsoNormal">I have lost the old email chain so had to
start a fresh one. The archived conversation can be found at
-
<a
href="http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2017-March/022733.html"
moz-do-not-send="true">
http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2017-March/022733.html</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l0 level1 lfo2"><!--[if !supportLists]--><span
style="mso-list:Ignore">1.<span style="font:7.0pt
"Times New Roman"">
</span></span><!--[endif]-->I have worked on all the
comments and fixed the bugs. Mainly bugs fixed are related
to sigprocmask() and changed the implementation such that
‘fd’ is not passed all the way down the call stack. Thus
minimizing function signature changes.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l0 level1 lfo2"><!--[if !supportLists]--><span
style="mso-list:Ignore">2.<span style="font:7.0pt
"Times New Roman"">
</span></span><!--[endif]-->Patch supports all OS’es.
Consolidated all Posix compliant OS’s implementation in
os_posix.cpp.<o:p></o:p></p>
<p class="MsoListParagraph"><o:p> </o:p></p>
<p class="MsoListParagraph"
style="text-indent:-.25in;mso-list:l0 level1 lfo2"><!--[if !supportLists]--><span
style="mso-list:Ignore">3.<span style="font:7.0pt
"Times New Roman"">
</span></span><!--[endif]-->The patch is tested on Windows
and Linux. Working on testing it on other OS’es.<o:p></o:p></p>
<p class="MsoListParagraph"><o:p> </o:p></p>
<p class="MsoNormal">Let me know if this version looks clean
and correct.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal">Kishor<o:p></o:p></p>
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