Hi guys, I have two questions regarding the OPcache interned strings bugger, I hope this mailing list is the right place to ask them, else feel free to redirect me to a more fitting place. 1. What is the logic behind the assigned strings buffer size and the actually usable size? When using powers of 2, it seems to be exactly 75% of it being usable, but for values between powers of 2, the usable buffer size seems to increase by exactly what was added to the setting, so that the used percentage increases until the next power of 2 is reached. So basically it is possible that an increase of the settings value leads to a decrease of the actually usable strings buffer. I'm just wondering about what the remaining <=25% are used for, whether using a power of 2 is preferable, or the opposite to have a batter ratio. To avoid confusion it may be reasonable to add the <=25% always to the usage statistics output, so that setting and statistics match. Also Asked on stackoverflow: https://stackoverflow.com/questions/67853338/opcache-interned-strings-buffer-size-lower-than-opcache-interned-strings-buffer 2. I have a PHP8.1 instance where I can increase the interned strings buffer size as much as I want, it is always nearly fully used based on the statistics. Currently it's 256 MiB assigned, 100% used with 512 MiB overall OPcache size ~90% used. This doesn't look reasonable, as the interned strings buffer is also meant to reduce the actual OPcache usage (? bundling strings), so it looks wrong that it is used with more MiB than the remaining OPcache. Or is it somehow expected that every smaller and larger fraction is a string is stored in the interned strings buffer as long as it is available, so that it basically always fills up? If so, how can one estimate a good size for ones individual instance? Best regards, Micha
