Date: Sun, 09 Sep 2018 20:16:19 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 222639] fork: Time it takes to allocate random PID approach infinity as num_processes approach PID_MAX (related to: sysctl kern.randompid) Message-ID: <bug-222639-227-UpqElf2NNP@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-222639-227@https.bugs.freebsd.org/bugzilla/> References: <bug-222639-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D222639 Conrad Meyer <cem@freebsd.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mjoras@freebsd.org --- Comment #2 from Conrad Meyer <cem@freebsd.org> --- (In reply to Marie Helene Kvello-Aune from comment #0) > Prequisite: Change how PIDs are tracked and allocated. Implement a bitmap= of PIDs > (I'm currently working on this) which is updated whenever anything in the= PID > namespace changes (a new PID/session ID/etc is created, or a PID/session = ID/etc > is considered available again). > The bitmap should be an array of 4096 uint32_t where each bit represents = a PID. > A set (on) bit indicates an available PID. IIRC, there was some earlier effort to bitmap-ify PIDs. I'm not sure where that went. CC'ing Matt, who might remember if there is any work that can be reused (or if I am misremembering and the work got committed already). If not, we have some abstractions for bitmaps in the kernel already which should probably be used in place of a raw u32 array =E2=80=94 see BITSET(9)= (if fixed size is ok) or vmem(9) (which in spite of the name is actually a general purpose allocater of integers in some range). Apologies if you have already thought of this or discovered it since the 2017-09 description I responded = to :-). --=20 You are receiving this mail because: You are the assignee for the bug.=
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