Date: Thu, 19 Oct 2017 06:08:32 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 223059] [patch] consider skipped 2 pages in sw_nblks and add size check before blist_alloc Message-ID: <bug-223059-8-Z6BXBUhnYN@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-223059-8@https.bugs.freebsd.org/bugzilla/> References: <bug-223059-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D223059 --- Comment #1 from Alan Cox <alc@FreeBSD.org> --- Testing "(sp->sw_nblks - sp->sw_used >=3D npages)" before every call to blist_alloc() is of no real benefit. In the common case, where there is available swap space, it is added overhead, albeit a tiny amount of overhea= d.=20 Only in the rare case, where there is no swap space available will it be of= any benefit. But, in that case, the gain is minimal. The hinting mechanism in= the blist code will quickly conclude that there is no available space, and retu= rn failure. In summary, the tiny amount of overhead in the common case is goi= ng to outweigh the gain in the rare case. --=20 You are receiving this mail because: You are the assignee for the bug.=
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