Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC

From
Jan Kara <hidden>
Date
2018-04-12 14:22:14
Also in
linux-ext4, linux-fsdevel, linux-mm, linux-xfs, nvdimm
Reply to
Michael Kerrisk (man-pages), 2018-04-12
Hello Michael!

On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
Hello Jan,

I have applied your patch, and tweaked the text a little, and pushed
the result to the git repo.
Thanks!
quoted
+.B MAP_SHARED
+type will silently ignore this flag.
+This flag is supported only for files supporting DAX (direct mapping of persistent
+memory). For other files, creating mapping with this flag results in
+.B EOPNOTSUPP
+error. Shared file mappings with this flag provide the guarantee that while
+some memory is writeably mapped in the address space of the process, it will
+be visible in the same file at the same offset even after the system crashes or
+is rebooted. This allows users of such mappings to make data modifications
+persistent in a more efficient way using appropriate CPU instructions.
It feels like there's a word missing/unclear wording in the previous
line, before "using". Without that word, the sentence feels a bit
ambiguous.

Should it be:

persistent in a more efficient way *through the use of* appropriate
CPU instructions.

or:

persistent in a more efficient way *than using* appropriate CPU instructions.

?

Is suspect the first is correct, but need to check.
Yes, the first is correct.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR
Thread (32 messages) 32 messages, 8 authors, last reply 2018-04-13
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help