Date: Sun, 19 May 2019 16:11:41 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 219216] sched_bind() blocks if the entropy pool is starved Message-ID: <bug-219216-227-r9NtMNEKVr@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-219216-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219216 --- Comment #10 from Conrad Meyer <cem@freebsd.org> --- rand_harvestq has had CPU reduced significantly in 12.x timeframe — previously it was attempting to obtain far more entropy and far more often than it actually needed. This was in part due to conservative estimates (r338293) and in part due to bugs in random read (r338292, r339492). r287023, r334450 may also be relevant. If you have a concurrent reader, rand_harvestq will fight it for the global Fortuna state mutex on head today (and spin while waiting). You are somewhat saved by READ_RANDOM_UIO dropping the Fortuna lock every 4kB (PAGE_SIZE). I have a revision proposed to reduce this conflict further: https://people.freebsd.org/~cem/rand_harvestq.png https://reviews.freebsd.org/D20313 -- You are receiving this mail because: You are the assignee for the bug.home | help
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