Re: [PATCH v4] mm: add replace_page_cache_page() function
From: KAMEZAWA Hiroyuki <hidden>
Date: 2011-01-19 00:48:13
Also in:
linux-fsdevel, lkml
On Wed, 19 Jan 2011 09:27:33 +0900 Daisuke Nishimura [off-list ref] wrote:
On Tue, 18 Jan 2011 15:28:44 -0800 Andrew Morton [off-list ref] wrote:quoted
On Tue, 18 Jan 2011 12:18:11 +0100 Miklos Szeredi [off-list ref] wrote:quoted
+int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) +{ + int error; + struct mem_cgroup *memcg = NULL;I'm suspecting that the unneeded initialisation was added to suppress a warning?No. It's necessary for mem_cgroup_{prepare|end}_migration(). mem_cgroup_prepare_migration() will return without doing anything in "if (mem_cgroup_disabled()" case(iow, "memcg" is not overwritten), but mem_cgroup_end_migration() depends on the value of "memcg" to decide whether prepare_migration has succeeded or not. This may not be a good implementation, but IMHO I'd like to to initialize valuable before using it in general.
I think it can be initlized in mem_cgroup_prepare_migration(). I'll send patch later. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>