* Re: + pg_uncached-is-ia64-only.patch added to -mm tree [not found] <200604070421.k374LXFs011197@shell0.pdx.osdl.net> @ 2006-04-07 4:48 ` KAMEZAWA Hiroyuki 2006-04-07 4:52 ` Andrew Morton 0 siblings, 1 reply; 5+ messages in thread From: KAMEZAWA Hiroyuki @ 2006-04-07 4:48 UTC (permalink / raw) To: linux-kernel; +Cc: akpm, jbarnes, jes, nickpiggin, tony.luck, mm-commits Hi, Andrew On Thu, 06 Apr 2006 21:20:26 -0700 akpm@osdl.org wrote: > > The patch titled > > PG_uncached is ia64 only > > has been added to the -mm tree. Its filename is > > pg_uncached-is-ia64-only.patch > > See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find > out what to do about this > in include/linux/mmzone.h == #elif BITS_PER_LONG == 64 /* * with 64 bit flags field, there's plenty of room. */ #define FLAGS_RESERVED 32 #else == it looks this is used here. #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED #endif I'm not sure but please compile check FLAGS_RESRVED with SPARSEMEM or just #if (BITS_PER_LONG > 32) /* 64-bit only flags. we can use full low 32bits */ #define PG_uncached 31 #endif Hm..Is this ugly ? :( -Kame > > From: Andrew Morton <akpm@osdl.org> > > As Nick points out, only ia64 uses PG_uncached. So we can push it up into the > higher 32-bits of page->flgs and make room for another flag on 32-bit > machines. > > Cc: "Luck, Tony" <tony.luck@intel.com> > Cc: Jesse Barnes <jbarnes@sgi.com> > Cc: Jes Sorensen <jes@trained-monkey.org> > Cc: Nick Piggin <nickpiggin@yahoo.com.au> > Signed-off-by: Andrew Morton <akpm@osdl.org> > --- > > include/linux/page-flags.h | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletion(-) > > diff -puN include/linux/page-flags.h~pg_uncached-is-ia64-only include/linux/page-flags.h > --- devel/include/linux/page-flags.h~pg_uncached-is-ia64-only 2006-04-06 21:17:16.000000000 -0700 > +++ devel-akpm/include/linux/page-flags.h 2006-04-06 21:18:31.000000000 -0700 > @@ -7,6 +7,8 @@ > > #include <linux/percpu.h> > #include <linux/cache.h> > + > +#include <asm/types.h> > #include <asm/pgtable.h> > > /* > @@ -86,7 +88,10 @@ > #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ > #define PG_reclaim 17 /* To be reclaimed asap */ > #define PG_nosave_free 18 /* Free, should not be written */ > -#define PG_uncached 19 /* Page has been mapped as uncached */ > + > +#if (BITS_PER_LONG > 32) > +#define PG_uncached 32 /* Page has been mapped as uncached */ > +#endif > > /* > * Global page accounting. One instance per CPU. Only unsigned longs are > _ > > Patches currently in -mm which might be from akpm@osdl.org are > > select-warning-fixes.patch > config_net=n-build-fix.patch > git-acpi.patch > acpi-update-asus_acpi-driver-registration-fix.patch > acpi-memory-hotplug-cannot-manage-_crs-with-plural-resoureces.patch > catch-notification-of-memory-add-event-of-acpi-via-container-driver-register-start-func-for-memory-device.patch > catch-notification-of-memory-add-event-of-acpi-via-container-driveravoid-redundant-call-add_memory.patch > sony_apci-resume.patch > powernow-k8-crash-workaround.patch > git-drm.patch > bt866-build-fix.patch > connector-exports.patch > git-ia64.patch > git-libata-all.patch > pci-error-recovery-e1000-network-device-driver.patch > pcmcia-remove-unneeded-forward-declarations.patch > git-scsi-misc.patch > megaraid-unused-variable.patch > git-sas-jg.patch > git-sas-jg-build-hack.patch > git-watchdog.patch > arm-add_memory-build-fix.patch > acx1xx-wireless-driver.patch > ext3-ext3-in-kernel-block-number-type-fixes-fix.patch > sync_file_range-use-unsigned-for-flags.patch > timer-initialisation-fix.patch > timer-initialisation-fix-tidy.patch > s3c24xx-gpio-led-support-tidy.patch > make-tty_insert_flip_string_flags-a-non-gpl-export.patch > prune_one_dentry-tweaks.patch > sys_kexec_load-naming-fixups.patch > hangcheck-remove-monotomic_clock-on-x86.patch > knfsd-nfsd4-limit-number-of-delegations-handed-out-fix.patch > pi-futex-futex-code-cleanups-fix.patch > reiser4.patch > kgdb-core-lite-add-reboot-command.patch > kgdb-8250-fix.patch > nr_blockdev_pages-in_interrupt-warning.patch > device-suspend-debug.patch > revert-tty-buffering-comment-out-debug-code.patch > slab-leaks3-default-y.patch > x86-kmap_atomic-debugging.patch > pg_uncached-is-ia64-only.patch > > - > To unsubscribe from this list: send the line "unsubscribe mm-commits" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: + pg_uncached-is-ia64-only.patch added to -mm tree 2006-04-07 4:48 ` + pg_uncached-is-ia64-only.patch added to -mm tree KAMEZAWA Hiroyuki @ 2006-04-07 4:52 ` Andrew Morton 2006-04-07 4:59 ` David S. Miller ` (2 more replies) 0 siblings, 3 replies; 5+ messages in thread From: Andrew Morton @ 2006-04-07 4:52 UTC (permalink / raw) To: KAMEZAWA Hiroyuki Cc: linux-kernel, jbarnes, jes, nickpiggin, tony.luck, mm-commits KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > Hi, Andrew > > On Thu, 06 Apr 2006 21:20:26 -0700 > akpm@osdl.org wrote: > > > > > The patch titled > > > > PG_uncached is ia64 only > > > > has been added to the -mm tree. Its filename is > > > > pg_uncached-is-ia64-only.patch > > > > See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find > > out what to do about this > > > > in include/linux/mmzone.h > == > #elif BITS_PER_LONG == 64 > /* > * with 64 bit flags field, there's plenty of room. > */ > #define FLAGS_RESERVED 32 > > #else OK. > > it looks this is used here. > > #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED > #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED > #endif > > I'm not sure but please compile check FLAGS_RESRVED with SPARSEMEM or > Yes, that test won't trigger. > > #if (BITS_PER_LONG > 32) /* 64-bit only flags. we can use full > low 32bits */ > #define PG_uncached 31 > #endif > > Hm..Is this ugly ? :( It's easier to change FLAGS_RESERVED ;) diff -puN include/linux/page-flags.h~pg_uncached-is-ia64-only include/linux/page-flags.h --- devel/include/linux/page-flags.h~pg_uncached-is-ia64-only 2006-04-06 21:50:51.000000000 -0700 +++ devel-akpm/include/linux/page-flags.h 2006-04-06 21:50:51.000000000 -0700 @@ -7,6 +7,8 @@ #include <linux/percpu.h> #include <linux/cache.h> +#include <linux/types.h> + #include <asm/pgtable.h> /* @@ -86,7 +88,10 @@ #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ #define PG_reclaim 17 /* To be reclaimed asap */ #define PG_nosave_free 18 /* Free, should not be written */ -#define PG_uncached 19 /* Page has been mapped as uncached */ + +#if (BITS_PER_LONG > 32) +#define PG_uncached 32 /* Page has been mapped as uncached */ +#endif /* * Global page accounting. One instance per CPU. Only unsigned longs are diff -puN include/linux/mmzone.h~pg_uncached-is-ia64-only include/linux/mmzone.h --- devel/include/linux/mmzone.h~pg_uncached-is-ia64-only 2006-04-06 21:50:56.000000000 -0700 +++ devel-akpm/include/linux/mmzone.h 2006-04-06 21:51:12.000000000 -0700 @@ -457,7 +457,7 @@ extern struct zone *next_zone(struct zon /* * with 64 bit flags field, there's plenty of room. */ -#define FLAGS_RESERVED 32 +#define FLAGS_RESERVED 24 #else _ ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: + pg_uncached-is-ia64-only.patch added to -mm tree 2006-04-07 4:52 ` Andrew Morton @ 2006-04-07 4:59 ` David S. Miller 2006-04-07 5:40 ` KAMEZAWA Hiroyuki 2006-04-08 15:41 ` Andy Whitcroft 2 siblings, 0 replies; 5+ messages in thread From: David S. Miller @ 2006-04-07 4:59 UTC (permalink / raw) To: linux-kernel, akpm Cc: kamezawa.hiroyu, jbarnes, jes, nickpiggin, tony.luck, mm-commits From: Andrew Morton <akpm@osdl.org> Date: Thu, 6 Apr 2006 21:52:42 -0700 > It's easier to change FLAGS_RESERVED ;) It reminds me that I need to do something about the fact that Sparc64 makes use of bits 24-->32 currently to record the cpu that performs cpu stores into and thus dirties the D-cache for a pagecache page. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: + pg_uncached-is-ia64-only.patch added to -mm tree 2006-04-07 4:52 ` Andrew Morton 2006-04-07 4:59 ` David S. Miller @ 2006-04-07 5:40 ` KAMEZAWA Hiroyuki 2006-04-08 15:41 ` Andy Whitcroft 2 siblings, 0 replies; 5+ messages in thread From: KAMEZAWA Hiroyuki @ 2006-04-07 5:40 UTC (permalink / raw) To: linux-kernel; +Cc: akpm, jbarnes, jes, nickpiggin, tony.luck, mm-commits On Thu, 6 Apr 2006 21:52:42 -0700 Andrew Morton <akpm@osdl.org> wrote: > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > -#define FLAGS_RESERVED 32 > +#define FLAGS_RESERVED 24 > Oh..we get more 8bits flags on 64bit machines !!! but could you reserve 30bits now ? This is my understanding.. == At the first look, SPARSEMEM with ia64 #define SECTION_SIZE_BITS (30) #define MAX_PHYSMEM_BITS (50) so SECTIONS_SHIFT = 50 - 30 = 20bits. 20bits of page->flags is used for SPARSEMEM's section id. sgi have NODES_SHIFT=8, and always ZONES_SHIFT=2 . At worst, 20 + 8 + 2 = 30bits should be used. but.. extra code is here.. == #if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED #define NODES_WIDTH NODES_SHIFT #else #define NODES_WIDTH 0 #endif == So, node-id is not encoded into flags. In this case, == <snip> #define FLAGS_HAS_NODE (NODES_WIDTH > 0 || NODES_SHIFT == 0) <snip> static inline unsigned long page_to_nid(struct page *page) { if (FLAGS_HAS_NODE) return (page->flags >> NODES_PGSHIFT) & NODES_MASK; else return page_zone(page)->zone_pgdat->node_id; } == page_zone(page) looks up zone from zone_table[]. If FLAGS_HAS_NODE=0, zone_table indexing is this. == (page->flags >> (offset of zone bit)) & ((1 << (SECTIONS_SHIFT + ZONES_SHIFT)) - 1) See above, SECTIONS_SHIFT + ZONES_SHIFT = 22bits. so, many ia64 people has to use 32M(22bits * 8bytes) zone_table[] ??? please fix if I'm wrong ...this is complicated. -Kame ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: + pg_uncached-is-ia64-only.patch added to -mm tree 2006-04-07 4:52 ` Andrew Morton 2006-04-07 4:59 ` David S. Miller 2006-04-07 5:40 ` KAMEZAWA Hiroyuki @ 2006-04-08 15:41 ` Andy Whitcroft 2 siblings, 0 replies; 5+ messages in thread From: Andy Whitcroft @ 2006-04-08 15:41 UTC (permalink / raw) To: Andrew Morton Cc: KAMEZAWA Hiroyuki, linux-kernel, jbarnes, jes, nickpiggin, tony.luck, mm-commits Andrew Morton wrote: > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > >>Hi, Andrew >> >>On Thu, 06 Apr 2006 21:20:26 -0700 >>akpm@osdl.org wrote: >> >> >>>The patch titled >>> >>> PG_uncached is ia64 only >>> >>>has been added to the -mm tree. Its filename is >>> >>> pg_uncached-is-ia64-only.patch >>> >>>See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find >>>out what to do about this >>> >> >>in include/linux/mmzone.h >>== >>#elif BITS_PER_LONG == 64 >>/* >> * with 64 bit flags field, there's plenty of room. >> */ >>#define FLAGS_RESERVED 32 >> >>#else > > > OK. > > >>it looks this is used here. >> >>#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED >>#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED >>#endif >> >>I'm not sure but please compile check FLAGS_RESRVED with SPARSEMEM or >> > > > Yes, that test won't trigger. > > >>#if (BITS_PER_LONG > 32) /* 64-bit only flags. we can use full >> low 32bits */ >>#define PG_uncached 31 >>#endif >> >>Hm..Is this ugly ? :( > > > It's easier to change FLAGS_RESERVED ;) > > diff -puN include/linux/page-flags.h~pg_uncached-is-ia64-only include/linux/page-flags.h > --- devel/include/linux/page-flags.h~pg_uncached-is-ia64-only 2006-04-06 21:50:51.000000000 -0700 > +++ devel-akpm/include/linux/page-flags.h 2006-04-06 21:50:51.000000000 -0700 > @@ -7,6 +7,8 @@ > > #include <linux/percpu.h> > #include <linux/cache.h> > +#include <linux/types.h> > + > #include <asm/pgtable.h> > > /* > @@ -86,7 +88,10 @@ > #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ > #define PG_reclaim 17 /* To be reclaimed asap */ > #define PG_nosave_free 18 /* Free, should not be written */ > -#define PG_uncached 19 /* Page has been mapped as uncached */ > + > +#if (BITS_PER_LONG > 32) > +#define PG_uncached 32 /* Page has been mapped as uncached */ > +#endif As Hiroyuki-san points out we can need up to 30 bits to encode large 64 bit machines right now. Reducing the space available for FIELDS but reducing FLAGS_RESERVED for 64 bit machines will negativly impact them when SPARSEMEM is enabled. I think it makes much more sense here to use the bits which have been released by the movement of the FIELDS upwards in the 64 bit case. 32 bit -------------------------------| FIELDS | FLAGS | 64 bit | FIELDS | ?????? FLAGS | 63 32 0 Logically we should in the general case have FLAGS_RESERVED in 64 bit be the value for 32 bit + 32; currently 9 + 32. If we desire to have 64 bit only flags then it seems keeping FLAGS_RESERVED at 32 for 64 bit would leave '32 bit FIELDS' segment free for those flags. In short with the current values of FLAGS_RESERVED I would think starting at 31 working downwards towards the 'common'/32 bit flags would be the most logical. Cheers. -apw ^ permalink raw reply [flat|nested] 5+ messages in thread
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2006-04-07 4:48 ` + pg_uncached-is-ia64-only.patch added to -mm tree KAMEZAWA Hiroyuki
2006-04-07 4:52 ` Andrew Morton
2006-04-07 4:59 ` David S. Miller
2006-04-07 5:40 ` KAMEZAWA Hiroyuki
2006-04-08 15:41 ` Andy Whitcroft
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