From: "J. Bruce Fields" <bfields@redhat.com>
To: linux-nfs@vger.kernel.org
Cc: "J. Bruce Fields" <bfields@redhat.com>
Subject: [PATCH 2/2] nfsd: give out fewer session slots as limit approaches
Date: Mon, 25 Sep 2017 09:21:44 -0400 [thread overview]
Message-ID: <1506345704-9486-3-git-send-email-bfields@redhat.com> (raw)
In-Reply-To: <1506345704-9486-1-git-send-email-bfields@redhat.com>
From: "J. Bruce Fields" <bfields@redhat.com>
Instead of granting client's full requests until we hit our DRC size
limit and then failing CREATE_SESSIONs (and hence mounts) completely,
start granting clients smaller slot tables as we approach the limit.
The factor chosen here is pretty much arbitrary.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/nfsd/nfs4state.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 28e5bded6a4b..2fe930e92545 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1472,6 +1472,11 @@ static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca)
spin_lock(&nfsd_drc_lock);
avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION,
nfsd_drc_max_mem - nfsd_drc_mem_used);
+ /*
+ * Never use more than a third of the remaining memory,
+ * unless it's the only way to give this client a slot:
+ */
+ avail = clamp_t(int, avail, slotsize, avail/3);
num = min_t(int, num, avail / slotsize);
nfsd_drc_mem_used += num * slotsize;
spin_unlock(&nfsd_drc_lock);
--
2.13.5
next prev parent reply other threads:[~2017-09-25 13:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-25 13:21 [PATCH 0/2] tweak knfsd session slot table sizing J. Bruce Fields
2017-09-25 13:21 ` [PATCH 1/2] nfsd: increase DRC cache limit J. Bruce Fields
2017-09-25 13:21 ` J. Bruce Fields [this message]
2019-09-19 1:08 ` [PATCH 2/2] nfsd: give out fewer session slots as limit approaches NeilBrown
2019-09-19 16:22 ` J. Bruce Fields
2019-09-19 17:17 ` J. Bruce Fields
2019-09-19 18:41 ` J. Bruce Fields
2019-09-20 6:15 ` [PATCH 1/2] nfsd: handle drc over-allocation gracefully NeilBrown
2019-09-20 6:33 ` [PATCH 1/2 - vers2] " NeilBrown
2019-09-20 6:36 ` [PATCH - 2/2] nfsd: degraded slot-count more gracefully as allocation nears exhaustion NeilBrown
2019-09-20 16:28 ` [PATCH 1/2 - vers2] nfsd: handle drc over-allocation gracefully J. Bruce Fields
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