Message-ID: <55771909.2020005@intel.com>
Date: Tue, 09 Jun 2015 09:49:13 -0700
From: Dave Hansen <dave.hansen@intel.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
MIME-Version: 1.0
To: Ingo Molnar <mingo@kernel.org>, Mel Gorman <mgorman@suse.de>
CC: Andrew Morton <akpm@linux-foundation.org>, Rik van Riel <riel@redhat.com>,
        Hugh Dickins <hughd@google.com>, Minchan Kim <minchan@kernel.org>,
        Andi Kleen <andi@firstfloor.org>, H Peter Anvin <hpa@zytor.com>,
        Linux-MM <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 0/3] TLB flush multiple pages per IPI v5
References: <1433767854-24408-1-git-send-email-mgorman@suse.de> <20150608174551.GA27558@gmail.com> <20150609084739.GQ26425@suse.de> <20150609103231.GA11026@gmail.com> <20150609112055.GS26425@suse.de> <20150609124328.GA23066@gmail.com> <5577078B.2000503@intel.com>
In-Reply-To: <5577078B.2000503@intel.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 851
Lines: 19

On 06/09/2015 08:34 AM, Dave Hansen wrote:
> 2. We should measure flushing of ascending, adjacent virtual addresses
>    mapped with 4k pages since that is the normal case.  Perhaps
>    vmalloc(16MB) or something.

Now that I think about this a bit more, we really have two different
patterns here:
1. flush_tlb_mm_range() style, which is contiguous virtual address
   flushing from an unmap-style operation.
2. Mel's new try_to_unmap_one() style, which are going to be relatively
   random virtual addresses.

So, the "ascending adjacent" case is still interesting, but it wouldn't
cover Mel's new case.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/