From: "Simmons, James A." <simmonsja@ornl.gov>
To: 'Dan Carpenter' <dan.carpenter@oracle.com>,
Julia Lawall <julia.lawall@lip6.fr>
Cc: "devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>,
"Dilger, Andreas" <andreas.dilger@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"kernel-janitors@vger.kernel.org"
<kernel-janitors@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Drokin, Oleg" <oleg.drokin@intel.com>,
"lustre-devel@lists.lustre.org" <lustre-devel@lists.lustre.org>
Subject: RE: LIBCFS_ALLOC
Date: Tue, 30 Jun 2015 14:56:21 +0000 [thread overview]
Message-ID: <d2c4fda0148a4e579b5636b586d32fbe@EXCHCS32.ornl.gov> (raw)
In-Reply-To: <20150628215408.GG28762@mwanda>
>Yeah. You're right. Doing a vmalloc() when kmalloc() doesn't have even
>a tiny sliver of RAM isn't going to work. It's easier to use
>libcfs_kvzalloc() everywhere, but it's probably the wrong thing.
The original reason we have the vmalloc water mark wasn't so much the
issue of memory exhaustion but to handle the case of memory fragmentation.
Some sites had after a extended period of time started to see failures of
allocating even 32K using kmalloc. In our latest development branch we moved
away from using a water mark to always try kmalloc first and if it fails then we
try vmalloc. At ORNL we ran into severe performance issues when we entered
vmalloc territory. It has been discussed before on what might replace vmalloc
handling in the case of kmalloc fails but no solution has been worked out.
next prev parent reply other threads:[~2015-06-30 14:56 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-20 16:58 [PATCH 00/12] Use !x to check for kzalloc failure Julia Lawall
2015-06-20 16:58 ` [PATCH 01/12] staging: lustre: fid: " Julia Lawall
2015-06-23 8:25 ` Dilger, Andreas
2015-06-23 9:23 ` Dan Carpenter
2015-06-23 9:35 ` Julia Lawall
2015-06-23 9:57 ` Dan Carpenter
2015-06-23 10:51 ` Julia Lawall
2015-06-24 20:14 ` [lustre-devel] " Simmons, James A.
2015-06-23 22:03 ` Joe Perches
2015-06-23 22:11 ` Joe Perches
2015-06-28 6:52 ` LIBCFS_ALLOC Julia Lawall
2015-06-28 21:54 ` LIBCFS_ALLOC Dan Carpenter
2015-06-30 14:56 ` Simmons, James A. [this message]
2015-06-30 15:01 ` LIBCFS_ALLOC Julia Lawall
2015-07-02 22:25 ` [lustre-devel] LIBCFS_ALLOC Simmons, James A.
2015-07-03 11:52 ` Dilger, Andreas
2015-06-30 17:38 ` LIBCFS_ALLOC Dan Carpenter
2015-06-30 21:26 ` [lustre-devel] LIBCFS_ALLOC Dilger, Andreas
2015-06-20 16:59 ` [PATCH 02/12] staging: lustre: fld: Use !x to check for kzalloc failure Julia Lawall
2015-06-20 16:59 ` [PATCH 03/12] staging: lustre: lclient: " Julia Lawall
2015-06-20 16:59 ` [PATCH 04/12] staging: lustre: ldlm: " Julia Lawall
2015-06-20 16:59 ` [PATCH 05/12] staging: lustre: lmv: " Julia Lawall
2015-06-20 16:59 ` [PATCH 06/12] staging: lustre: lov: " Julia Lawall
2015-06-20 16:59 ` [PATCH 07/12] staging: lustre: mdc: " Julia Lawall
2015-06-20 16:59 ` [PATCH 08/12] staging: lustre: mgc: " Julia Lawall
2015-06-20 16:59 ` [PATCH 09/12] staging: lustre: obdclass: " Julia Lawall
2015-06-21 10:02 ` walter harms
2015-06-21 10:29 ` Julia Lawall
2015-06-21 11:58 ` walter harms
2015-06-20 16:59 ` [PATCH 10/12] staging: lustre: obdecho: " Julia Lawall
2015-06-20 16:59 ` [PATCH 11/12] staging: lustre: osc: " Julia Lawall
2015-06-20 16:59 ` [PATCH 12/12] staging: lustre: ptlrpc: " Julia Lawall
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