From: Meelap Shah Date: Tue, 17 Jul 2007 11:04:39 +0000 (-0700) Subject: knfsd: nfsd4: vary maximum delegation limit based on RAM size X-Git-Tag: v2.6.23-rc1~655 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2f1a551dea8b37c2e0cb886885c250fb703e9d8;p=pandora-kernel.git knfsd: nfsd4: vary maximum delegation limit based on RAM size Our original NFSv4 delegation policy was to give out a read delegation on any open when it was possible to. Since the lifetime of a delegation isn't limited to that of an open, a client may quite reasonably hang on to a delegation as long as it has the inode cached. This becomes an obvious problem the first time a client's inode cache approaches the size of the server's total memory. Our first quick solution was to add a hard-coded limit. This patch makes a mild incremental improvement by varying that limit according to the server's total memory size, allowing at most 4 delegations per megabyte of RAM. My quick back-of-the-envelope calculation finds that in the worst case (where every delegation is for a different inode), a delegation could take about 1.5K, which would make the worst case usage about 6% of memory. The new limit works out to be about the same as the old on a 1-gig server. [akpm@linux-foundation.org: Don't needlessly bloat vmlinux] [akpm@linux-foundation.org: Make it right for highmem machines] Signed-off-by: "J. Bruce Fields" Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed