From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leonid Yegoshin Subject: Re: [PATCH 6/8] mm/highmem: make kmap cache coloring aware Date: Tue, 22 Jul 2014 12:35:15 -0700 Message-ID: <53CEBCF3.9010208@imgtec.com> References: <1406055673-10100-1-git-send-email-jcmvbkbc@gmail.com> <1406055673-10100-7-git-send-email-jcmvbkbc@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1406055673-10100-7-git-send-email-jcmvbkbc@gmail.com> Sender: owner-linux-mm@kvack.org To: Max Filippov Cc: linux-xtensa@linux-xtensa.org, Chris Zankel , Marc Gauthier , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-mips@linux-mips.org, David Rientjes List-Id: linux-arch.vger.kernel.org On 07/22/2014 12:01 PM, Max Filippov wrote: > From: Leonid Yegoshin > > Provide hooks that allow architectures with aliasing cache to align > mapping address of high pages according to their color. Such architectures > may enforce similar coloring of low- and high-memory page mappings and > reuse existing cache management functions to support highmem. > > Cc: linux-mm@kvack.org > Cc: linux-arch@vger.kernel.org > Cc: linux-mips@linux-mips.org > Cc: David Rientjes > Signed-off-by: Leonid Yegoshin > [ Max: extract architecture-independent part of the original patch, clean > up checkpatch and build warnings. ] > Signed-off-by: Max Filippov > --- > Changes since the initial version: > - define set_pkmap_color(pg, cl) as do { } while (0) instead of /* */; > - rename is_no_more_pkmaps to no_more_pkmaps; > - change 'if (count > 0)' to 'if (count)' to better match the original > code behavior; > > mm/highmem.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > > diff --git a/mm/highmem.c b/mm/highmem.c > index b32b70c..88fb62e 100644 > --- a/mm/highmem.c > +++ b/mm/highmem.c > @@ -44,6 +44,14 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx); > */ > #ifdef CONFIG_HIGHMEM > > +#ifndef ARCH_PKMAP_COLORING > +#define set_pkmap_color(pg, cl) do { } while (0) > +#define get_last_pkmap_nr(p, cl) (p) > +#define get_next_pkmap_nr(p, cl) (((p) + 1) & LAST_PKMAP_MASK) > +#define no_more_pkmaps(p, cl) (!(p)) > +#define get_next_pkmap_counter(c, cl) ((c) - 1) > +#endif > + > unsigned long totalhigh_pages __read_mostly; > EXPORT_SYMBOL(totalhigh_pages); > > @@ -161,19 +169,24 @@ static inline unsigned long map_new_virtual(struct page *page) > { > unsigned long vaddr; > int count; > + int color __maybe_unused; > + > + set_pkmap_color(page, color); > + last_pkmap_nr = get_last_pkmap_nr(last_pkmap_nr, color); > > start: > count = LAST_PKMAP; > /* Find an empty entry */ > for (;;) { > - last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK; > - if (!last_pkmap_nr) { > + last_pkmap_nr = get_next_pkmap_nr(last_pkmap_nr, color); > + if (no_more_pkmaps(last_pkmap_nr, color)) { > flush_all_zero_pkmaps(); > count = LAST_PKMAP; > } > if (!pkmap_count[last_pkmap_nr]) > break; /* Found a usable entry */ > - if (--count) > + count = get_next_pkmap_counter(count, color); > + if (count) > continue; > > /* I would like to return back to "if (count >0)". The reason is in easy way to jump through the same coloured pages - next element is calculated via decrementing by non "1" value of colours and it can easy become negative on last page available: #define get_next_pkmap_counter(c,cl) (c - FIX_N_COLOURS) where FIX_N_COLOURS is a max number of page colours. Besides that it is a good practice in stopping cycle. - Leonid. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailapp01.imgtec.com ([195.59.15.196]:50762 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756535AbaGVTfW (ORCPT ); Tue, 22 Jul 2014 15:35:22 -0400 Message-ID: <53CEBCF3.9010208@imgtec.com> Date: Tue, 22 Jul 2014 12:35:15 -0700 From: Leonid Yegoshin MIME-Version: 1.0 Subject: Re: [PATCH 6/8] mm/highmem: make kmap cache coloring aware References: <1406055673-10100-1-git-send-email-jcmvbkbc@gmail.com> <1406055673-10100-7-git-send-email-jcmvbkbc@gmail.com> In-Reply-To: <1406055673-10100-7-git-send-email-jcmvbkbc@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Max Filippov Cc: linux-xtensa@linux-xtensa.org, Chris Zankel , Marc Gauthier , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-mips@linux-mips.org, David Rientjes Message-ID: <20140722193515.Up8zBMbIBkpAEdnM7n18WZRqfE7xwx8q-J-aeMwjskQ@z> On 07/22/2014 12:01 PM, Max Filippov wrote: > From: Leonid Yegoshin > > Provide hooks that allow architectures with aliasing cache to align > mapping address of high pages according to their color. Such architectures > may enforce similar coloring of low- and high-memory page mappings and > reuse existing cache management functions to support highmem. > > Cc: linux-mm@kvack.org > Cc: linux-arch@vger.kernel.org > Cc: linux-mips@linux-mips.org > Cc: David Rientjes > Signed-off-by: Leonid Yegoshin > [ Max: extract architecture-independent part of the original patch, clean > up checkpatch and build warnings. ] > Signed-off-by: Max Filippov > --- > Changes since the initial version: > - define set_pkmap_color(pg, cl) as do { } while (0) instead of /* */; > - rename is_no_more_pkmaps to no_more_pkmaps; > - change 'if (count > 0)' to 'if (count)' to better match the original > code behavior; > > mm/highmem.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > > diff --git a/mm/highmem.c b/mm/highmem.c > index b32b70c..88fb62e 100644 > --- a/mm/highmem.c > +++ b/mm/highmem.c > @@ -44,6 +44,14 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx); > */ > #ifdef CONFIG_HIGHMEM > > +#ifndef ARCH_PKMAP_COLORING > +#define set_pkmap_color(pg, cl) do { } while (0) > +#define get_last_pkmap_nr(p, cl) (p) > +#define get_next_pkmap_nr(p, cl) (((p) + 1) & LAST_PKMAP_MASK) > +#define no_more_pkmaps(p, cl) (!(p)) > +#define get_next_pkmap_counter(c, cl) ((c) - 1) > +#endif > + > unsigned long totalhigh_pages __read_mostly; > EXPORT_SYMBOL(totalhigh_pages); > > @@ -161,19 +169,24 @@ static inline unsigned long map_new_virtual(struct page *page) > { > unsigned long vaddr; > int count; > + int color __maybe_unused; > + > + set_pkmap_color(page, color); > + last_pkmap_nr = get_last_pkmap_nr(last_pkmap_nr, color); > > start: > count = LAST_PKMAP; > /* Find an empty entry */ > for (;;) { > - last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK; > - if (!last_pkmap_nr) { > + last_pkmap_nr = get_next_pkmap_nr(last_pkmap_nr, color); > + if (no_more_pkmaps(last_pkmap_nr, color)) { > flush_all_zero_pkmaps(); > count = LAST_PKMAP; > } > if (!pkmap_count[last_pkmap_nr]) > break; /* Found a usable entry */ > - if (--count) > + count = get_next_pkmap_counter(count, color); > + if (count) > continue; > > /* I would like to return back to "if (count >0)". The reason is in easy way to jump through the same coloured pages - next element is calculated via decrementing by non "1" value of colours and it can easy become negative on last page available: #define get_next_pkmap_counter(c,cl) (c - FIX_N_COLOURS) where FIX_N_COLOURS is a max number of page colours. Besides that it is a good practice in stopping cycle. - Leonid. From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 22 Jul 2014 21:37:12 +0200 (CEST) Received: from mailapp01.imgtec.com ([195.59.15.196]:24049 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6863548AbaGVTf0Ehf40 (ORCPT ); Tue, 22 Jul 2014 21:35:26 +0200 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 8F0FD1AB5F0EB; Tue, 22 Jul 2014 20:35:14 +0100 (IST) Received: from BAMAIL02.ba.imgtec.org (192.168.66.28) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.195.1; Tue, 22 Jul 2014 20:35:18 +0100 Received: from [192.168.65.146] (192.168.65.146) by bamail02.ba.imgtec.org (192.168.66.28) with Microsoft SMTP Server (TLS) id 14.3.174.1; Tue, 22 Jul 2014 12:35:15 -0700 Message-ID: <53CEBCF3.9010208@imgtec.com> Date: Tue, 22 Jul 2014 12:35:15 -0700 From: Leonid Yegoshin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Max Filippov CC: , Chris Zankel , "Marc Gauthier" , , , , , David Rientjes Subject: Re: [PATCH 6/8] mm/highmem: make kmap cache coloring aware References: <1406055673-10100-1-git-send-email-jcmvbkbc@gmail.com> <1406055673-10100-7-git-send-email-jcmvbkbc@gmail.com> In-Reply-To: <1406055673-10100-7-git-send-email-jcmvbkbc@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.65.146] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 41496 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: Leonid.Yegoshin@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 07/22/2014 12:01 PM, Max Filippov wrote: > From: Leonid Yegoshin > > Provide hooks that allow architectures with aliasing cache to align > mapping address of high pages according to their color. Such architectures > may enforce similar coloring of low- and high-memory page mappings and > reuse existing cache management functions to support highmem. > > Cc: linux-mm@kvack.org > Cc: linux-arch@vger.kernel.org > Cc: linux-mips@linux-mips.org > Cc: David Rientjes > Signed-off-by: Leonid Yegoshin > [ Max: extract architecture-independent part of the original patch, clean > up checkpatch and build warnings. ] > Signed-off-by: Max Filippov > --- > Changes since the initial version: > - define set_pkmap_color(pg, cl) as do { } while (0) instead of /* */; > - rename is_no_more_pkmaps to no_more_pkmaps; > - change 'if (count > 0)' to 'if (count)' to better match the original > code behavior; > > mm/highmem.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > > diff --git a/mm/highmem.c b/mm/highmem.c > index b32b70c..88fb62e 100644 > --- a/mm/highmem.c > +++ b/mm/highmem.c > @@ -44,6 +44,14 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx); > */ > #ifdef CONFIG_HIGHMEM > > +#ifndef ARCH_PKMAP_COLORING > +#define set_pkmap_color(pg, cl) do { } while (0) > +#define get_last_pkmap_nr(p, cl) (p) > +#define get_next_pkmap_nr(p, cl) (((p) + 1) & LAST_PKMAP_MASK) > +#define no_more_pkmaps(p, cl) (!(p)) > +#define get_next_pkmap_counter(c, cl) ((c) - 1) > +#endif > + > unsigned long totalhigh_pages __read_mostly; > EXPORT_SYMBOL(totalhigh_pages); > > @@ -161,19 +169,24 @@ static inline unsigned long map_new_virtual(struct page *page) > { > unsigned long vaddr; > int count; > + int color __maybe_unused; > + > + set_pkmap_color(page, color); > + last_pkmap_nr = get_last_pkmap_nr(last_pkmap_nr, color); > > start: > count = LAST_PKMAP; > /* Find an empty entry */ > for (;;) { > - last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK; > - if (!last_pkmap_nr) { > + last_pkmap_nr = get_next_pkmap_nr(last_pkmap_nr, color); > + if (no_more_pkmaps(last_pkmap_nr, color)) { > flush_all_zero_pkmaps(); > count = LAST_PKMAP; > } > if (!pkmap_count[last_pkmap_nr]) > break; /* Found a usable entry */ > - if (--count) > + count = get_next_pkmap_counter(count, color); > + if (count) > continue; > > /* I would like to return back to "if (count >0)". The reason is in easy way to jump through the same coloured pages - next element is calculated via decrementing by non "1" value of colours and it can easy become negative on last page available: #define get_next_pkmap_counter(c,cl) (c - FIX_N_COLOURS) where FIX_N_COLOURS is a max number of page colours. Besides that it is a good practice in stopping cycle. - Leonid.