On (03/24/15 14:03), akpm@xxxxxxxxxxxxxxxxxxxx wrote: > The patch titled > Subject: zsmalloc: do not remap dst page while prepare next src page > has been added to the -mm tree. Its filename is > zsmalloc-do-not-remap-dst-page-while-prepare-next-src-page.patch > > This patch should soon appear at > http://ozlabs.org/~akpm/mmots/broken-out/zsmalloc-do-not-remap-dst-page-while-prepare-next-src-page.patch > and later at > http://ozlabs.org/~akpm/mmotm/broken-out/zsmalloc-do-not-remap-dst-page-while-prepare-next-src-page.patch > Hello Stephen, Heesub Shin has reported that this patch causes BUG_ON on ARM (with CONFIG_DEBUG_HIGHMEM enabled). Could you please revert it in linux-next 20150325? -ss > ------------------------------------------------------ > From: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> > Subject: zsmalloc: do not remap dst page while prepare next src page > > The object may belong to different pages. zs_object_copy() handles this > case and maps a new source page (get_next_page() and kmap_atomic()) when > object crosses boundaries of the current source page. But it also > performs unnecessary kunmap/kmap_atomic of the destination page (it > remains unchanged), which can be avoided. > > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> > Cc: Minchan Kim <minchan@xxxxxxxxxx> > Cc: Nitin Gupta <ngupta@xxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > mm/zsmalloc.c | 2 -- > 1 file changed, 2 deletions(-) > > diff -puN mm/zsmalloc.c~zsmalloc-do-not-remap-dst-page-while-prepare-next-src-page mm/zsmalloc.c > --- a/mm/zsmalloc.c~zsmalloc-do-not-remap-dst-page-while-prepare-next-src-page > +++ a/mm/zsmalloc.c > @@ -1538,12 +1538,10 @@ static void zs_object_copy(unsigned long > break; > > if (s_off + size >= PAGE_SIZE) { > - kunmap_atomic(d_addr); > kunmap_atomic(s_addr); > s_page = get_next_page(s_page); > BUG_ON(!s_page); > s_addr = kmap_atomic(s_page); > - d_addr = kmap_atomic(d_page); > s_size = class->size - written; > s_off = 0; > } else { > _ > > Patches currently in -mm which might be from sergey.senozhatsky@xxxxxxxxx are > > zram-cosmetic-zram_attr_ro-code-formatting-tweak.patch > zram-use-idr-instead-of-zram_devices-array.patch > zram-factor-out-device-reset-from-reset_store.patch > zram-reorganize-code-layout.patch > zram-add-dynamic-device-add-remove-functionality.patch > zram-add-dynamic-device-add-remove-functionality-fix.patch > zram-remove-max_num_devices-limitation.patch > zram-report-every-added-and-removed-device.patch > zram-trivial-correct-flag-operations-comment.patch > zram-return-zram-device_id-value-from-zram_add.patch > zram-introduce-automatic-device_id-generation.patch > zram-introduce-automatic-device_id-generation-fix.patch > zram-do-not-let-user-enforce-new-device-dev_id.patch > zsmalloc-decouple-handle-and-object.patch > zsmalloc-factor-out-obj_.patch > zsmalloc-support-compaction.patch > zsmalloc-adjust-zs_almost_full.patch > zram-support-compaction.patch > zsmalloc-record-handle-in-page-private-for-huge-object.patch > zsmalloc-add-fullness-into-stat.patch > zsmalloc-zsmalloc-documentation.patch > zram-remove-num_migrated-device-attr.patch > zram-move-compact_store-to-sysfs-functions-area.patch > zram-use-generic-start-end-io-accounting.patch > zram-describe-device-attrs-in-documentation.patch > zram-export-new-io_stat-sysfs-attrs.patch > zram-export-new-mm_stat-sysfs-attrs.patch > zram-deprecate-zram-attrs-sysfs-nodes.patch > zsmalloc-remove-synchronize_rcu-from-zs_compact.patch > zsmalloc-remove-extra-cond_resched-in-__zs_compact.patch > zsmalloc-do-not-remap-dst-page-while-prepare-next-src-page.patch > zsmalloc-micro-optimize-zs_object_copy.patch > cpumask-dont-perform-while-loop-in-cpumask_next_and.patch > lib-lz4-pull-out-constant-tables.patch > > -- > To unsubscribe from this list: send the line "unsubscribe mm-commits" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
