After commit 77573fa310d9 ("fs: Kill DCACHE_DONTCACHE dentry even if
DCACHE_REFERENCED is set"), changes to DAX policy will take effect
as soon as all references to this file are gone.
Update the documentation accordingly.
Signed-off-by: Hao Li <redacted>
---
Changes in v2:
* simplify sentences and fix style problems.
Documentation/filesystems/dax.txt | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
@@ -83,20 +83,9 @@ Summary directories. This has runtime constraints and limitations that are described in 6) below.- 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX flag,- the change in behaviour for existing regular files may not occur- immediately. If the change must take effect immediately, the administrator- needs to:-- a) stop the application so there are no active references to the data set- the policy change will affect-- b) evict the data set from kernel caches so it will be re-instantiated when- the application is restarted. This can be achieved by:-- i. drop-caches- ii. a filesystem unmount and mount cycle- iii. a system reboot+ 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX+ flag, the change to existing regular files won't take effect until the+ files are closed by all processes. Details
From: Ira Weiny <hidden> Date: 2021-01-06 05:46:38
On Wed, Jan 06, 2021 at 09:50:00AM +0800, Hao Li wrote:
After commit 77573fa310d9 ("fs: Kill DCACHE_DONTCACHE dentry even if
DCACHE_REFERENCED is set"), changes to DAX policy will take effect
as soon as all references to this file are gone.
Update the documentation accordingly.
Signed-off-by: Hao Li <redacted>
@@ -83,20 +83,9 @@ Summary directories. This has runtime constraints and limitations that are described in 6) below.- 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX flag,- the change in behaviour for existing regular files may not occur- immediately. If the change must take effect immediately, the administrator- needs to:-- a) stop the application so there are no active references to the data set- the policy change will affect-- b) evict the data set from kernel caches so it will be re-instantiated when- the application is restarted. This can be achieved by:-- i. drop-caches- ii. a filesystem unmount and mount cycle- iii. a system reboot+ 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX+ flag, the change to existing regular files won't take effect until the+ files are closed by all processes. Details
From: Jonathan Corbet <corbet@lwn.net> Date: 2021-01-11 20:00:41
On Tue, 5 Jan 2021 21:45:41 -0800
Ira Weiny [off-list ref] wrote:
On Wed, Jan 06, 2021 at 09:50:00AM +0800, Hao Li wrote:
quoted
After commit 77573fa310d9 ("fs: Kill DCACHE_DONTCACHE dentry even if
DCACHE_REFERENCED is set"), changes to DAX policy will take effect
as soon as all references to this file are gone.
Update the documentation accordingly.
Signed-off-by: Hao Li <redacted>