Date: Wed, 03 Mar 2021 19:11:03 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 253992] ufsdirhash_build() sleeps with directory vnode locked due to M_WAITOK Message-ID: <bug-253992-227-lM2YzWhtFM@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-253992-227@https.bugs.freebsd.org/bugzilla/>
index | next in thread | previous in thread | raw e-mail
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253992 --- Comment #3 from Mark Johnston <markj@FreeBSD.org> --- Right, UMA has defaulted to the FIRSTTOUCH policy since https://reviews.freebsd.org/D22831 . Indeed, the policy is kind of questionable. It is strict first-touch, i.e., always returns local memory. First-touch policies implemented using domainsets do not have this property unless explicitly requested, so if you allocate a page with e.g., DOMAINSET_PREF(0), we will return memory from other domains if necessary to avoid sleeping. I am not sure why FIRSTTOUCH has this strict implementation. Originally it was used for bucket zones, which are always NOWAIT. And until recently UMA did not have special handling for cross-domain frees. We could consider adding a new (default) policy which is not strict. It is likely necessary for ZFS to work well on NUMA systems, since its buffer cache memory is allocated from UMA. That is a larger problem though. In this case though the pressure is apparently caused by a kernel memory leak. -- You are receiving this mail because: You are the assignee for the bug.home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-253992-227-lM2YzWhtFM>