/* * fs/bfs/file.c * BFS file operations. * Copyright (C) 1999,2000 Tigran Aivazian * * Make the file block allocation algorithm understand the size * of the underlying block device. * Copyright (C) 2007 Dmitri Vorobiev * */ #include #include #include "bfs.h" #undef DEBUG #ifdef DEBUG #define dprintf(x...) printf(x) #else #define dprintf(x...) #endif const struct file_operations bfs_file_operations = { .llseek = generic_file_llseek, .read_iter = generic_file_read_iter, .write_iter = generic_file_write_iter, .mmap = generic_file_mmap, .splice_read = generic_file_splice_read, }; static int bfs_move_block(unsigned long from, unsigned long to, struct super_block *sb) { struct buffer_head *bh, *new; bh = sb_bread(sb, from); if (!bh) return -EIO; new = sb_getblk(sb, to); memcpy(new->b_data, bh->b_data, bh->b_size); mark_buffer_dirty(new); bforget(bh); brelse(new); return 0; } static int bfs_move_blocks(struct super_block *sb, unsigned long start, unsigned long end, unsigned long where) { unsigned long i; dprintf("%08lx-%08lx->%08lx\n", start, end, where); for (i = start; i <= end; i++) if(bfs_move_block(i, where + i, sb)) { dprintf("failed to move block %08lx -> %08lx\n", i, where + i); return -EIO; } return 0; } static int bfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create) { unsigned long phys; int err; struct super_block *sb = inode->i_sb; struct bfs_sb_info *info = BFS_SB(sb); struct bfs_inode_info *bi = BFS_I(inode); phys = bi->i_sblock + block; if (!create) { if (phys <= bi->i_eblock) { dprintf("c=%d, b=%08lx, phys=%09lx (granted)\n", create, (unsigned long)block, phys); map_bh(bh_result, sb, phys); } return 0; } /* * If the file is not empty and the requested block is within the * range of blocks allocated for this file, we can grant it. */ if (bi->i_sblock && (phys <= bi->i_eblock)) { dprintf("c=%d, b=%08lx, phys=%08lx (interim block granted)\n", create, (unsigned long)block, phys); map_bh(bh_result, sb, phys); return 0; } /* The file will be extended, so let's see if there is enough space. */ if (phys >= info->si_blocks) return -ENOSPC; /* The rest has to be protected against itself. */ mutex_lock(&info->bfs_lock); /* * If the last data block for this file is the last allocated * block, we can extend the file trivially, without moving it * anywhere. */ if (bi->i_eblock == info->si_lf_eblk) { dprintf("c=%d, b=%08lx, phys=%08lx (simple extension)\n", create, (unsigned long)block, phys); map_bh(bh_result, sb, phys); info->si_freeb -= phys - bi->i_eblock; info->si_lf_eblk = bi->i_eblock = phys; mark_inode_dirty(inode); err = 0; goto out; } /* Ok, we have to move this entire file to the next free block. */ phys = info->si_lf_eblk + 1; if (phys + block >= info->si_blocks) { err = -ENOSPC; goto out; } if (bi->i_sblock) { err = bfs_move_blocks(inode->i_sb, bi->i_sblock, bi->i_eblock, phys); if (err) { dprintf("failed to move ino=%08lx -> fs corruption\n", inode->i_ino); goto out; } } else err = 0; dprintf("c=%d, b=%08lx, phys=%08lx (moved)\n", create, (unsigned long)block, phys); bi->i_sblock = phys; phys += block; info->si_lf_eblk = bi->i_eblock = phys; /* * This assumes nothing can write the inode back while we are here * and thus update inode->i_blocks! (XXX) */ info->si_freeb -= bi->i_eblock - bi->i_sblock + 1 - inode->i_blocks; mark_inode_dirty(inode); map_bh(bh_result, sb, phys); out: mutex_unlock(&info->bfs_lock); return err; } static int bfs_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, bfs_get_block, wbc); } static int bfs_readpage(struct file *file, struct page *page) { return block_read_full_page(page, bfs_get_block); } static void bfs_write_failed(struct address_space *mapping, loff_t to) { struct inode *inode = mapping->host; if (to > inode->i_size) truncate_pagecache(inode, inode->i_size); } static int bfs_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { int ret; ret = block_write_begin(mapping, pos, len, flags, pagep, bfs_get_block); if (unlikely(ret)) bfs_write_failed(mapping, pos + len); return ret; } static sector_t bfs_bmap(struct address_space *mapping, sector_t block) { return generic_block_bmap(mapping, block, bfs_get_block); } const struct address_space_operations bfs_aops = { .readpage = bfs_readpage, .writepage = bfs_writepage, .write_begin = bfs_write_begin, .write_end = generic_write_end, .bmap = bfs_bmap, }; const struct inode_operations bfs_file_inops; option>
authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2017-02-03 14:18:39 -0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-02-04 00:11:08 +0100
commit6e978b22efa1db9f6e71b24440b5f1d93e968ee3 (patch)
treec666f7a26b860674848949e39a610222b0723f89 /tools/perf/pmu-events/arch/powerpc/power8
parent3c223c19aea85d3dda1416c187915f4a30b04b1f (diff)
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in HWP mode, even if running under sustained 100% utilization. This occurs when the HWP.EPP (Energy Performance Preference) is set to "balance_power" (0x80) -- the default on most systems. It occurs because the platform BIOS may erroneously enable an energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not recommended to be enabled on this SKU. On the failing systems, this BIOS issue was not discovered when the desktop motherboard was tested with Windows, because the BIOS also neglects to provide the ACPI/CPPC table, that Windows requires to enable HWP, and so Windows runs in legacy P-state mode, where this setting has no effect. Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and so it runs in HWP mode, exposing this incorrect BIOS configuration. There are several ways to address this problem. First, Linux can also run in legacy P-state mode on this system. As intel_pstate is how Linux enables HWP, booting with "intel_pstate=disable" will run in acpi-cpufreq/ondemand legacy p-state mode. Or second, the "performance" governor can be used with intel_pstate, which will modify HWP.EPP to 0. Or third, starting in 4.10, the /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference attribute in can be updated from "balance_power" to "performance". Or fourth, apply this patch, which fixes the erroneous setting of MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default configuration to function as designed. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Reviewed-by: Len Brown <len.brown@intel.com> Cc: 4.6+ <stable@vger.kernel.org> # 4.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'tools/perf/pmu-events/arch/powerpc/power8')