linux-kernel - Re: [PATCH] x86/mm: Don't flush the TLB on #WP pmd fixups

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20121120123156.GA15798@gmail.com>
Date:	Tue, 20 Nov 2012 13:31:56 +0100
From:	Ingo Molnar <mingo@...nel.org>
To:	David Rientjes <rientjes@...gle.com>
Cc:	Mel Gorman <mgorman@...e.de>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Turner <pjt@...gle.com>,
	Lee Schermerhorn <Lee.Schermerhorn@...com>,
	Christoph Lameter <cl@...ux.com>,
	Rik van Riel <riel@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Johannes Weiner <hannes@...xchg.org>,
	Hugh Dickins <hughd@...gle.com>
Subject: Re: [PATCH] x86/mm: Don't flush the TLB on #WP pmd fixups


* Ingo Molnar <mingo@...nel.org> wrote:

> * Ingo Molnar <mingo@...nel.org> wrote:
> 
> > numa/core profile:
> > 
> >     95.66%  perf-1201.map     [.] 0x00007fe4ad1c8fc7                 
> >      1.70%  libjvm.so         [.] 0x0000000000381581                 
> >      0.59%  [vdso]            [.] 0x0000000000000607                 
> >      0.19%  [kernel]          [k] do_raw_spin_lock                   
> >      0.11%  [kernel]          [k] generic_smp_call_function_interrupt
> >      0.11%  [kernel]          [k] timekeeping_get_ns.constprop.7     
> >      0.08%  [kernel]          [k] ktime_get                          
> >      0.06%  [kernel]          [k] get_cycles                         
> >      0.05%  [kernel]          [k] __native_flush_tlb                 
> >      0.05%  [kernel]          [k] rep_nop                            
> >      0.04%  perf              [.] add_hist_entry.isra.9              
> >      0.04%  [kernel]          [k] rcu_check_callbacks                
> >      0.04%  [kernel]          [k] ktime_get_update_offsets           
> >      0.04%  libc-2.15.so      [.] __strcmp_sse2                      
> > 
> > No page fault overhead (see the page fault rate further below) 
> > - the NUMA scanning overhead shows up only through some mild 
> > TLB flush activity (which I'll fix btw).
> 
> The patch attached below should get rid of that mild TLB 
> flushing activity as well.

This has further increased SPECjbb from 203k/sec to 207k/sec, 
i.e. it's now 5% faster than mainline - THP enabled.

The profile is now totally flat even during a full 32-WH SPECjbb 
run, with the highest overhead entries left all related to timer 
IRQ processing or profiling. That is on a system that should be 
very close to yours.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/