[PATCH 0/1] ipc/util.{c,h}: Use binary search for max_idx

From: Manfred Spraul
Date: Sun Apr 25 2021 - 03:52:32 EST


2nd version of the patch:
@Andrew: Could you add the patch to your mm tree, as candidate for
linux-next?

Note:
I have tried to remove the ids->max_idx cache entirely. Unfortunately,
this causes a significant slow-down of semstat(,,IPC_STAT):
* no object allocated, no ipcmni_extended: +50%
* no object allocated, with ipcmni_extended: +80%
* 30 objects allocated, with large gaps, no ipcmni_extended:
+350%
Thus I haven't removed ids->max_id.


--
Manfred