Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Minchan Kim
Hello Weijie, On Thu, Sep 26, 2013 at 04:48:03PM +0800, Weijie Yang wrote: > On Thu, Sep 26, 2013 at 3:57 PM, Minchan Kim wrote: > > On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: > >> On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim wrote: > >> > Hello Weigie, > >> > > >> > On Wed,

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Bob Liu
On Thu, Sep 26, 2013 at 4:48 PM, Weijie Yang wrote: > On Thu, Sep 26, 2013 at 3:57 PM, Minchan Kim wrote: >> On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: >>> On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim wrote: >>> > Hello Weigie, >>> > >>> > On Wed, Sep 25, 2013 at 05:33:43PM

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Weijie Yang
On Thu, Sep 26, 2013 at 3:57 PM, Minchan Kim wrote: > On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: >> On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim wrote: >> > Hello Weigie, >> > >> > On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: >> >> On Wed, Sep 25, 2013 at 4:31

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Minchan Kim
On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: > On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim wrote: > > Hello Weigie, > > > > On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: > >> On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu wrote: > >> > On Wed, Sep 25, 2013 at 4:09 PM,

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Weijie Yang
On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim wrote: > Hello Weigie, > > On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: >> On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu wrote: >> > On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang >> > wrote: >> >> I think I find a new issue, for integrity

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Weijie Yang
On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim minc...@kernel.org wrote: Hello Weigie, On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang weijie.yang...@gmail.com wrote:

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Minchan Kim
On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim minc...@kernel.org wrote: Hello Weigie, On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Weijie Yang
On Thu, Sep 26, 2013 at 3:57 PM, Minchan Kim minc...@kernel.org wrote: On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim minc...@kernel.org wrote: Hello Weigie, On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: On Wed,

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Bob Liu
On Thu, Sep 26, 2013 at 4:48 PM, Weijie Yang weijie.yang...@gmail.com wrote: On Thu, Sep 26, 2013 at 3:57 PM, Minchan Kim minc...@kernel.org wrote: On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim minc...@kernel.org wrote: Hello Weigie,

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-26 Thread Minchan Kim
Hello Weijie, On Thu, Sep 26, 2013 at 04:48:03PM +0800, Weijie Yang wrote: On Thu, Sep 26, 2013 at 3:57 PM, Minchan Kim minc...@kernel.org wrote: On Thu, Sep 26, 2013 at 03:26:33PM +0800, Weijie Yang wrote: On Thu, Sep 26, 2013 at 1:58 PM, Minchan Kim minc...@kernel.org wrote: Hello

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Minchan Kim
Hello Weigie, On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: > On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu wrote: > > On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang > > wrote: > >> I think I find a new issue, for integrity of this mail thread, I reply > >> to this mail. > >> > >> It

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Weijie Yang
On Wed, Sep 25, 2013 at 6:02 PM, Bob Liu wrote: > On Wed, Sep 25, 2013 at 5:33 PM, Weijie Yang wrote: >> On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu wrote: >>> On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang >>> wrote: I think I find a new issue, for integrity of this mail thread, I reply

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Bob Liu
On Wed, Sep 25, 2013 at 5:33 PM, Weijie Yang wrote: > On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu wrote: >> On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang >> wrote: >>> I think I find a new issue, for integrity of this mail thread, I reply >>> to this mail. >>> >>> It is a concurrence issue either,

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Weijie Yang
On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu wrote: > On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang wrote: >> I think I find a new issue, for integrity of this mail thread, I reply >> to this mail. >> >> It is a concurrence issue either, when duplicate store and reclaim >> concurrentlly. >> >> zswap

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Bob Liu
On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang wrote: > I think I find a new issue, for integrity of this mail thread, I reply > to this mail. > > It is a concurrence issue either, when duplicate store and reclaim > concurrentlly. > > zswap entry x with offset A is already stored in zswap backend.

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Weijie Yang
I think I find a new issue, for integrity of this mail thread, I reply to this mail. It is a concurrence issue either, when duplicate store and reclaim concurrentlly. zswap entry x with offset A is already stored in zswap backend. Consider the following scenario: thread 0: reclaim entry x (get

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Weijie Yang
I think I find a new issue, for integrity of this mail thread, I reply to this mail. It is a concurrence issue either, when duplicate store and reclaim concurrentlly. zswap entry x with offset A is already stored in zswap backend. Consider the following scenario: thread 0: reclaim entry x (get

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Bob Liu
On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang weijie.yang...@gmail.com wrote: I think I find a new issue, for integrity of this mail thread, I reply to this mail. It is a concurrence issue either, when duplicate store and reclaim concurrentlly. zswap entry x with offset A is already stored

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Weijie Yang
On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang weijie.yang...@gmail.com wrote: I think I find a new issue, for integrity of this mail thread, I reply to this mail. It is a concurrence issue either, when duplicate store and

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Bob Liu
On Wed, Sep 25, 2013 at 5:33 PM, Weijie Yang weijie.yang...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang weijie.yang...@gmail.com wrote: I think I find a new issue, for integrity of this mail thread, I reply

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Weijie Yang
On Wed, Sep 25, 2013 at 6:02 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep 25, 2013 at 5:33 PM, Weijie Yang weijie.yang...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang weijie.yang...@gmail.com wrote: I

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-09-25 Thread Minchan Kim
Hello Weigie, On Wed, Sep 25, 2013 at 05:33:43PM +0800, Weijie Yang wrote: On Wed, Sep 25, 2013 at 4:31 PM, Bob Liu lliu...@gmail.com wrote: On Wed, Sep 25, 2013 at 4:09 PM, Weijie Yang weijie.yang...@gmail.com wrote: I think I find a new issue, for integrity of this mail thread, I reply

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-21 Thread Minchan Kim
Hello, On Tue, Aug 20, 2013 at 11:30:29PM +0800, Weijie Yang wrote: > 2013/8/19 Minchan Kim : > > On Mon, Aug 19, 2013 at 10:17:38AM +0800, Bob Liu wrote: > >> Hi Weijie, > >> > >> On 08/19/2013 12:14 AM, Weijie Yang wrote: > >> > I found a few bugs in zswap when I review Linux-3.11-rc5, and I

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-21 Thread Minchan Kim
Hello, On Tue, Aug 20, 2013 at 11:30:29PM +0800, Weijie Yang wrote: 2013/8/19 Minchan Kim minc...@kernel.org: On Mon, Aug 19, 2013 at 10:17:38AM +0800, Bob Liu wrote: Hi Weijie, On 08/19/2013 12:14 AM, Weijie Yang wrote: I found a few bugs in zswap when I review Linux-3.11-rc5, and I

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-20 Thread Weijie Yang
2013/8/19 Minchan Kim : > On Mon, Aug 19, 2013 at 10:17:38AM +0800, Bob Liu wrote: >> Hi Weijie, >> >> On 08/19/2013 12:14 AM, Weijie Yang wrote: >> > I found a few bugs in zswap when I review Linux-3.11-rc5, and I have >> > also some questions about it, described as following: >> > >> > BUG: >> >

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-20 Thread Weijie Yang
2013/8/19 Minchan Kim minc...@kernel.org: On Mon, Aug 19, 2013 at 10:17:38AM +0800, Bob Liu wrote: Hi Weijie, On 08/19/2013 12:14 AM, Weijie Yang wrote: I found a few bugs in zswap when I review Linux-3.11-rc5, and I have also some questions about it, described as following: BUG: 1.

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-18 Thread Minchan Kim
On Mon, Aug 19, 2013 at 10:17:38AM +0800, Bob Liu wrote: > Hi Weijie, > > On 08/19/2013 12:14 AM, Weijie Yang wrote: > > I found a few bugs in zswap when I review Linux-3.11-rc5, and I have > > also some questions about it, described as following: > > > > BUG: > > 1. A race condition when

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-18 Thread Bob Liu
Hi Weijie, On 08/19/2013 12:14 AM, Weijie Yang wrote: > I found a few bugs in zswap when I review Linux-3.11-rc5, and I have > also some questions about it, described as following: > > BUG: > 1. A race condition when reclaim a page > when a handle alloced from zbud, zbud considers this handle is

[BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-18 Thread Weijie Yang
I found a few bugs in zswap when I review Linux-3.11-rc5, and I have also some questions about it, described as following: BUG: 1. A race condition when reclaim a page when a handle alloced from zbud, zbud considers this handle is used validly by upper(zswap) and can be a candidate for reclaim.

[BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-18 Thread Weijie Yang
I found a few bugs in zswap when I review Linux-3.11-rc5, and I have also some questions about it, described as following: BUG: 1. A race condition when reclaim a page when a handle alloced from zbud, zbud considers this handle is used validly by upper(zswap) and can be a candidate for reclaim.

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-18 Thread Bob Liu
Hi Weijie, On 08/19/2013 12:14 AM, Weijie Yang wrote: I found a few bugs in zswap when I review Linux-3.11-rc5, and I have also some questions about it, described as following: BUG: 1. A race condition when reclaim a page when a handle alloced from zbud, zbud considers this handle is used

Re: [BUG REPORT] ZSWAP: theoretical race condition issues

2013-08-18 Thread Minchan Kim
On Mon, Aug 19, 2013 at 10:17:38AM +0800, Bob Liu wrote: Hi Weijie, On 08/19/2013 12:14 AM, Weijie Yang wrote: I found a few bugs in zswap when I review Linux-3.11-rc5, and I have also some questions about it, described as following: BUG: 1. A race condition when reclaim a page