Date: Wed, 09 Jan 2019 17:54:08 +0000 From: bugzilla-noreply@freebsd.org To: emulation@FreeBSD.org Subject: [Bug 230160] linuxulator doesn't implement madvise(MADV_DONTNEED) correctly Message-ID: <bug-230160-4077-P4O934ncSk@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-230160-4077@https.bugs.freebsd.org/bugzilla/> References: <bug-230160-4077@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D230160 --- Comment #2 from Mark Johnston <markj@FreeBSD.org> --- Yes, we should probably just extend our madvise(2) to implement Linux's MADV_DONTNEED. Some care is needed, as we currently assume that madvise(2)= is advisory and so may be ignored for pages in some transient busy state.=20 However, we cannot correctly do this when implementing Linux MADV_DONTNEED = for private anonymous memory. I don't really like the idea of having a generic MADV_ZERO. First, Linux MADV_DONTNEED only "zeroes" the page if it belongs to a private mapping. P= ages belonging to shared mappings should be handled the same way as FreeBSD's MADV_DONTNEED, from my reading of the man page. So that name would be misleading. Second, I think it's pretty widely agreed that Linux's implementation choice here is a historical mistake. We should emulate it, = but I don't think it makes much sense to do so in a generic fashion. I'd just = add an undocumented MADV_DONTNEED_LINUX. --=20 You are receiving this mail because: You are the assignee for the bug.=
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