opcache.interned_strings_buffer either has no effect or opcache_get_status() / phpinfo() is wrong #11715

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1. gndk

   added

   Bug

   Status: Needs Triage

   on Jul 16, 2023
2. ndossche commented on Jul 16, 2023

   

   ndossche

   on Jul 16, 2023

   Last edited by ndossche

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   I just tried this and got a different, but equally weird result.
   I got 193752 used, 12388696 free. Sum that up and you get 12582448, which is just under 12MiB, less than the 16 I set it at 🤔

   EDIT: I don't understand this code:

   php-src/ext/opcache/ZendAccelerator.c

   Lines 2904 to 2906 in cbd903d

   	ZCSG(interned_strings).end =
   	(zend_string*)((char*)accel_shared_globals +
   	ZCG(accel_directives).interned_strings_buffer * 1024 * 1024);

   I would've expected this instead:

   		ZCSG(interned_strings).end =
   			(zend_string*)((char*)ZCSG(interned_strings).start +
   				ZCG(accel_directives).interned_strings_buffer * 1024 * 1024);

   i.e. to compute the end, instead of starting from the start of the struct, we start at the interned string table start. This makes more sense to me. And this yields the right result on my computer. But I'm not sure, I didn't look too deep into it yet as I'm out of time for today.

   EDIT 2: Wait but then this line is also wrong:

   php-src/ext/opcache/ZendAccelerator.c

   Line 2864 in cbd903d

   accel_shared_globals_size = ZCG(accel_directives).interned_strings_buffer * 1024 * 1024;

   I'm confused
3. ndossche

   added

   Extension: opcache

   Status: Verified

   and removed

   Status: Needs Triage

   on Jul 16, 2023
4. gndk commented on Jul 17, 2023

   

   gndk

   on Jul 17, 2023

   Last edited by gndk

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   Glad you could confirm!

   I'm confused

   Well, sorry to add to the confusion, but I actually had it set to 256 before (which I then realised was much too high), but even with that it still was stuck on the 6mb from my screenshot..
5. ndossche commented on Jul 17, 2023

   

   ndossche

   on Jul 17, 2023

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   I think I figured it out and will try to create a PR soon.
   There's two issues I think: the end calculation is wrong, and the memory usage/free reporting is using the wrong values.
   I think if I'm right, it makes sense you're seeing that 6MB behaviour.

   👍React with 👍1Reacted by gndk
6. ndossche

   linked a pull request that will close this issueFix GH-11715: opcache.interned_strings_buffer either has no effect or… #11717on Jul 17, 2023
7. ndossche

   added 2 commits that reference this issue on Jul 17, 2023

   Fix phpGH-11715: opcache.interned_strings_buffer either has no effect…

   ...

   This issue will close once commit d1693ec is merged into the 'master' branch.

   d1693ec

   Fix GH-11715: opcache.interned_strings_buffer either has no effect or…

   ...

   This issue will close once commit ee3f932 is merged into the 'master' branch.

   ee3f932
8. ndossche

   closed this as completedin ee3f932on Jul 21, 2023
9. ndossche

   added 2 commits that reference this issue on Jul 21, 2023

   Merge branch 'PHP-8.1' into PHP-8.2

   ...

   This issue will close once commit 404f1d3 is merged into the 'master' branch.

   404f1d3

   Merge branch 'PHP-8.2'

   ...

   This issue will close once commit e90c96b is merged into the 'master' branch.

   e90c96b