AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

sparc: clarify __GFP_NOFAIL allocation

Browse Source 
Commit 920c3ed741 ("[SPARC64]: Add basic infrastructure for MD
add/remove notification") has added __GFP_NOFAIL for the allocation
request but it hasn't mentioned why is this strict requirement really
needed.  The code was handling an allocation failure and propagated it
properly up the callchain so it is not clear why it is needed.

Dave has clarified the intention when I tried to remove the flag as not
being necessary:

: It is a serious failure.
:
: If we miss an MDESC update due to this allocation failure, the update
: is not an event which gets retransmitted so we will lose the updated
: machine description forever.
:
: We really need this allocation to succeed.

So add a comment to clarify the nofail flag and get rid of the failure
check because __GFP_NOFAIL allocation doesn't fail.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vipul Pandya <vipul@chelsio.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michal Hocko 2015-04-14 15:47:11 -07:00 committed by Linus Torvalds
parent 647757197c
commit f91e8d6d76
1 changed files with 11 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
arch/sparc/kernel/mdesc.c
View File

@ -130,26 +130,26 @@ static struct mdesc_mem_ops memblock_mdesc_ops = {
static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size)
{
unsigned int handle_size;
struct mdesc_handle *hp;
unsigned long addr;
void *base;
handle_size = (sizeof(struct mdesc_handle) -
sizeof(struct mdesc_hdr) +
mdesc_size);
/*
* Allocation has to succeed because mdesc update would be missed
* and such events are not retransmitted.
*/
base = kmalloc(handle_size + 15, GFP_KERNEL | __GFP_NOFAIL);
if (base) {
struct mdesc_handle *hp;
unsigned long addr;
addr = (unsigned long)base;
addr = (addr + 15UL) & ~15UL;
hp = (struct mdesc_handle *) addr;
mdesc_handle_init(hp, handle_size, base);
return hp;
}
return NULL;
return hp;
}
static void mdesc_kfree(struct mdesc_handle *hp)