Re: [PATCH -v2] mm: frontswap: fix a wrong if condition in frontswap_shrink

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 2012-09-27 19:35, Paul Bolle wrote:
On Fri, 2012-09-21 at 16:40 +0800, Zhenzhong Duan wrote:

@@ -275,7 +280,7 @@ static int __frontswap_shrink(unsigned long target_pages,
  	if (total_pages<= target_pages) {
  		/* Nothing to do */
  		*pages_to_unuse = 0;

I think setting pages_to_unuse to zero here is not needed. It is
initiated to zero in frontswap_shrink() and hasn't been touched since.
See my patch at https://lkml.org/lkml/2012/9/27/250.
Yes, it's unneeded. But I didn't see warning as you said in above link when run 'make V=1 mm/frontswap.o'.
-		return 0;
+		return 1;
  	}
  	total_pages_to_unuse = total_pages - target_pages;
  	return __frontswap_unuse_pages(total_pages_to_unuse, pages_to_unuse, type);
@@ -302,7 +307,7 @@ void frontswap_shrink(unsigned long target_pages)
  	spin_lock(&swap_lock);
  	ret = __frontswap_shrink(target_pages,&pages_to_unuse,&type);
  	spin_unlock(&swap_lock);
-	if (ret == 0&&  pages_to_unuse)
+	if (ret == 0)
  		try_to_unuse(type, true, pages_to_unuse);
  	return;
  }

Are you sure pages_to_unuse won't be zero here? I've stared quite a bit
at __frontswap_unuse_pages() and it's not obvious pages_to_unuse (there
also called unused) will never be zero when that function returns zero.
pages_to_unuse==0 means all pages need to be unused.

zduan

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>


[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]