From: "Jan Beulich" <JBeulich@suse.com>
To: Punit Agrawal <punit.agrawal@arm.com>
Cc: tim@xen.org, sstabellini@kernel.org, wei.liu2@citrix.com,
George.Dunlap@eu.citrix.com, andrew.cooper3@citrix.com,
ian.jackson@eu.citrix.com, xen-devel@lists.xen.org,
julien.grall@arm.com
Subject: Re: [For Xen-4.10 PATCH v2 3/3] Avoid excess icache flushes in populate_physmap() before domain has been created
Date: Fri, 26 May 2017 05:51:06 -0600 [thread overview]
Message-ID: <592832CA020000780015CCB6@prv-mh.provo.novell.com> (raw)
In-Reply-To: <20170526111407.13537-4-punit.agrawal@arm.com>
>>> On 26.05.17 at 13:14, <punit.agrawal@arm.com> wrote:
> populate_physmap() calls alloc_heap_pages() per requested
> extent. alloc_heap_pages() invalidates the entire icache per
> extent. During domain creation, the icache invalidations can be deffered
> until all the extents have been allocated as there is no risk of
> executing stale instructions from the icache.
>
> Introduce a new flag "MEMF_no_icache_flush" to be used to prevent
> alloc_heap_pages() from performing icache maintenance operations. Use
> the flag in populate_physmap() before the domain has been unpaused and
> perform required icache maintenance function at the end of the
> allocation.
>
> One concern is the lack of synchronisation around testing for
> "creation_finished". But it seems, in practice the window where it is
> out of sync should be small enough to not matter.
>
> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
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next prev parent reply other threads:[~2017-05-26 11:51 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-26 11:14 [For Xen-4.10 PATCH v2 0/3] Reduce unnecessary icache maintenance operations Punit Agrawal
2017-05-26 11:14 ` [For Xen-4.10 PATCH v2 1/3] Allow control of icache invalidations when calling flush_page_to_ram() Punit Agrawal
2017-05-26 11:14 ` [For Xen-4.10 PATCH v2 2/3] arm: p2m: Prevent redundant icache flushes Punit Agrawal
2017-05-26 11:14 ` [For Xen-4.10 PATCH v2 3/3] Avoid excess icache flushes in populate_physmap() before domain has been created Punit Agrawal
2017-05-26 11:51 ` Jan Beulich [this message]
2017-06-07 8:38 ` Jan Beulich
2017-06-07 8:59 ` Punit Agrawal
2017-06-07 9:34 ` [For Xen-4.10 PATCH] Ensure invalidate_icache() definition is visible only when !__ASSEMBLY__ Punit Agrawal
2017-06-07 10:37 ` Jan Beulich
2017-06-07 11:19 ` [For Xen-4.10 PATCH v2 3/3] Avoid excess icache flushes in populate_physmap() before domain has been created Andrew Cooper
2017-06-07 11:32 ` Julien Grall
2017-06-07 11:41 ` Punit Agrawal
2017-06-07 12:04 ` [For Xen-4.10 PATCH] memory: Re-introduce an erroneously dropped line Punit Agrawal
2017-06-07 12:13 ` Jan Beulich
2017-06-07 12:16 ` Julien Grall
2017-06-06 16:32 ` [For Xen-4.10 PATCH v2 0/3] Reduce unnecessary icache maintenance operations Julien Grall
2017-06-06 16:36 ` Jan Beulich
2017-06-06 18:51 ` Stefano Stabellini
2017-06-07 9:46 ` Punit Agrawal
2017-06-07 17:46 ` Stefano Stabellini
2017-06-07 17:47 ` Julien Grall
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