Date: Fri, 13 Oct 2023 23:53:54 GMT From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 7ec19caae5b0 - stable/13 - vfs: consult freevnodes in vnlru_kick_cond Message-ID: <202310132353.39DNrsoC032214@gitrepo.freebsd.org>
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The branch stable/13 has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=7ec19caae5b0044da963298d4ae79cfcf3ebaf01 commit 7ec19caae5b0044da963298d4ae79cfcf3ebaf01 Author: Mateusz Guzik <mjg@FreeBSD.org> AuthorDate: 2023-10-10 16:19:53 +0000 Commit: Mateusz Guzik <mjg@FreeBSD.org> CommitDate: 2023-10-13 23:48:13 +0000 vfs: consult freevnodes in vnlru_kick_cond If the count is high enough there is no point trying to produce more. Not going there reduces traffic on the vnode_list mtx. This further shaves total real time in a test mentioned in: 74be676d87745eb7 ("vfs: drop one vnode list lock trip during vnlru free recycle") -- 20 instances of find each creating 1 million vnodes, while total limit is set to 400k. Time goes down from ~41 to ~35 seconds. Sponsored by: Rubicon Communications, LLC ("Netgate") (cherry picked from commit 23ef25d25d989e7213bc1d3ef32b0f48a9eb2537) --- sys/kern/vfs_subr.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index 29b255b418e4..5ddbff77a221 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -1601,6 +1601,9 @@ static void vnlru_kick_cond(void) { + if (vnlru_read_freevnodes() > wantfreevnodes) + return; + if (vnlruproc_sig) return; mtx_lock(&vnode_list_mtx); @@ -1867,9 +1870,8 @@ vn_alloc_hard(struct mount *mp) } alloc: mtx_assert(&vnode_list_mtx, MA_NOTOWNED); - rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1; - if (vnlru_under(rnumvnodes, vlowat)) - vnlru_kick_cond(); + atomic_add_long(&numvnodes, 1); + vnlru_kick_cond(); return (uma_zalloc_smr(vnode_zone, M_WAITOK)); }
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