From: Dave Hansen <dave.hansen@intel.com>
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
Date: Mon, 08 Jun 2015 11:21:39 -0700 [thread overview]
Message-ID: <5575DD33.3000400@intel.com> (raw)
In-Reply-To: <20150608174551.GA27558@gmail.com>
On 06/08/2015 10:45 AM, Ingo Molnar wrote:
> As per my measurements the __flush_tlb_single() primitive (which you use in patch
> #2) is very expensive on most Intel and AMD CPUs. It barely makes sense for a 2
> pages and gets exponentially worse. It's probably done in microcode and its
> performance is horrible.
I discussed this a bit in commit a5102476a2. I'd be curious what
numbers you came up with.
But, don't we have to take in to account the cost of refilling the TLB
in addition to the cost of emptying it? The TLB size is historically
increasing on a per-core basis, so isn't this refill cost only going to
get worse?
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next prev parent reply other threads:[~2015-06-08 18:30 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-08 12:50 [PATCH 0/3] TLB flush multiple pages per IPI v5 Mel Gorman
2015-06-08 12:50 ` [PATCH 1/3] x86, mm: Trace when an IPI is about to be sent Mel Gorman
2015-06-08 12:50 ` [PATCH 2/3] mm: Send one IPI per CPU to TLB flush multiple pages that were recently unmapped Mel Gorman
2015-06-08 22:38 ` Andrew Morton
2015-06-09 11:07 ` Mel Gorman
2015-06-08 12:50 ` [PATCH 3/3] mm: Defer flush of writable TLB entries Mel Gorman
2015-06-08 17:45 ` [PATCH 0/3] TLB flush multiple pages per IPI v5 Ingo Molnar
2015-06-08 18:21 ` Dave Hansen [this message]
2015-06-08 19:52 ` Ingo Molnar
2015-06-08 20:03 ` Ingo Molnar
2015-06-08 21:07 ` Dave Hansen
2015-06-08 21:50 ` Ingo Molnar
2015-06-09 8:47 ` Mel Gorman
2015-06-09 10:32 ` Ingo Molnar
2015-06-09 11:20 ` Mel Gorman
2015-06-09 12:43 ` Ingo Molnar
2015-06-09 13:05 ` Mel Gorman
2015-06-10 8:51 ` Ingo Molnar
2015-06-10 9:08 ` Ingo Molnar
2015-06-10 10:15 ` Mel Gorman
2015-06-11 15:26 ` Ingo Molnar
2015-06-10 9:19 ` Mel Gorman
2015-06-09 15:34 ` Dave Hansen
2015-06-09 16:49 ` Dave Hansen
2015-06-09 21:14 ` Dave Hansen
2015-06-09 21:54 ` Linus Torvalds
2015-06-09 22:32 ` Mel Gorman
2015-06-09 22:35 ` Mel Gorman
2015-06-10 13:13 ` Andi Kleen
2015-06-10 16:17 ` Linus Torvalds
2015-06-10 16:42 ` Linus Torvalds
2015-06-10 17:24 ` Mel Gorman
2015-06-10 17:31 ` Linus Torvalds
2015-06-10 18:08 ` Josh Boyer
2015-06-10 17:07 ` Mel Gorman
2015-06-21 20:22 ` Kirill A. Shutemov
2015-06-25 11:48 ` Ingo Molnar
2015-06-25 18:36 ` Linus Torvalds
2015-06-25 19:15 ` Vlastimil Babka
2015-06-25 22:04 ` Linus Torvalds
2015-06-25 18:46 ` Dave Hansen
2015-06-26 9:08 ` Ingo Molnar
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