From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- drivers/mtd/lpddr/lpddr_cmds.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/mtd/lpddr/lpddr_cmds.c') diff --git a/drivers/mtd/lpddr/lpddr_cmds.c b/drivers/mtd/lpddr/lpddr_cmds.c index e22ca49583e7..a73ee12aad81 100644 --- a/drivers/mtd/lpddr/lpddr_cmds.c +++ b/drivers/mtd/lpddr/lpddr_cmds.c @@ -26,6 +26,7 @@ */ #include #include +#include static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len, size_t *retlen, u_char *buf); -- cgit v1.2.3 From c4e773764cead9358fd4b036d1b883fff3968513 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Sun, 18 Apr 2010 22:46:44 +0200 Subject: mtd: fix a huge latency problem in the MTD CFI and LPDDR flash drivers. The use of a memcpy() during a spinlock operation will cause very long thread context switch delays if the flash chip bandwidth is low and the data to be copied large, because a spinlock will disable preemption. For example: A flash with 6,5 MB/s bandwidth will cause under ubifs, which request sometimes 128 KiB (the flash erase size), a preemption delay of 20 milliseconds. High priority threads will not be served during this time, regardless whether this threads access the flash or not. This behavior breaks real time. The patch changes all the use of spin_lock operations for xxxx->mutex into mutex operations, which is exact what the name says and means. I have checked the code of the drivers and there is no use of atomic pathes like interrupt or timers. The mtdoops facility will also not be used by this drivers. So it is dave to replace the spin_lock against mutex. There is no performance regression since the mutex is normally not acquired. Changelog: 06.03.2010 First release 26.03.2010 Fix mutex[1] issue and tested it for compile failure Signed-off-by: Stefani Seibold Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/lpddr/lpddr_cmds.c | 79 +++++++++++++++++++++--------------------- 1 file changed, 39 insertions(+), 40 deletions(-) (limited to 'drivers/mtd/lpddr/lpddr_cmds.c') diff --git a/drivers/mtd/lpddr/lpddr_cmds.c b/drivers/mtd/lpddr/lpddr_cmds.c index e22ca49583e7..eb6f437ca9ec 100644 --- a/drivers/mtd/lpddr/lpddr_cmds.c +++ b/drivers/mtd/lpddr/lpddr_cmds.c @@ -106,8 +106,7 @@ struct mtd_info *lpddr_cmdset(struct map_info *map) /* those should be reset too since they create memory references. */ init_waitqueue_head(&chip->wq); - spin_lock_init(&chip->_spinlock); - chip->mutex = &chip->_spinlock; + mutex_init(&chip->mutex); chip++; } } @@ -143,7 +142,7 @@ static int wait_for_ready(struct map_info *map, struct flchip *chip, } /* OK Still waiting. Drop the lock, wait a while and retry. */ - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); if (sleep_time >= 1000000/HZ) { /* * Half of the normal delay still remaining @@ -158,17 +157,17 @@ static int wait_for_ready(struct map_info *map, struct flchip *chip, cond_resched(); timeo--; } - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); while (chip->state != chip_state) { /* Someone's suspended the operation: sleep */ DECLARE_WAITQUEUE(wait, current); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); schedule(); remove_wait_queue(&chip->wq, &wait); - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); } if (chip->erase_suspended || chip->write_suspended) { /* Suspend has occured while sleep: reset timeout */ @@ -229,20 +228,20 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) * it'll happily send us to sleep. In any case, when * get_chip returns success we're clear to go ahead. */ - ret = spin_trylock(contender->mutex); + ret = mutex_trylock(&contender->mutex); spin_unlock(&shared->lock); if (!ret) goto retry; - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); ret = chip_ready(map, contender, mode); - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); if (ret == -EAGAIN) { - spin_unlock(contender->mutex); + mutex_unlock(&contender->mutex); goto retry; } if (ret) { - spin_unlock(contender->mutex); + mutex_unlock(&contender->mutex); return ret; } spin_lock(&shared->lock); @@ -251,10 +250,10 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) * state. Put contender and retry. */ if (chip->state == FL_SYNCING) { put_chip(map, contender); - spin_unlock(contender->mutex); + mutex_unlock(&contender->mutex); goto retry; } - spin_unlock(contender->mutex); + mutex_unlock(&contender->mutex); } /* Check if we have suspended erase on this chip. @@ -264,10 +263,10 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) spin_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); schedule(); remove_wait_queue(&chip->wq, &wait); - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); goto retry; } @@ -336,10 +335,10 @@ static int chip_ready(struct map_info *map, struct flchip *chip, int mode) sleep: set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); schedule(); remove_wait_queue(&chip->wq, &wait); - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); return -EAGAIN; } } @@ -355,12 +354,12 @@ static void put_chip(struct map_info *map, struct flchip *chip) if (shared->writing && shared->writing != chip) { /* give back the ownership */ struct flchip *loaner = shared->writing; - spin_lock(loaner->mutex); + mutex_lock(&loaner->mutex); spin_unlock(&shared->lock); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); put_chip(map, loaner); - spin_lock(chip->mutex); - spin_unlock(loaner->mutex); + mutex_lock(&chip->mutex); + mutex_unlock(&loaner->mutex); wake_up(&chip->wq); return; } @@ -413,10 +412,10 @@ int do_write_buffer(struct map_info *map, struct flchip *chip, wbufsize = 1 << lpddr->qinfo->BufSizeShift; - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); ret = get_chip(map, chip, FL_WRITING); if (ret) { - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } /* Figure out the number of words to write */ @@ -477,7 +476,7 @@ int do_write_buffer(struct map_info *map, struct flchip *chip, } out: put_chip(map, chip); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -489,10 +488,10 @@ int do_erase_oneblock(struct mtd_info *mtd, loff_t adr) struct flchip *chip = &lpddr->chips[chipnum]; int ret; - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); ret = get_chip(map, chip, FL_ERASING); if (ret) { - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } send_pfow_command(map, LPDDR_BLOCK_ERASE, adr, 0, NULL); @@ -504,7 +503,7 @@ int do_erase_oneblock(struct mtd_info *mtd, loff_t adr) goto out; } out: put_chip(map, chip); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -517,10 +516,10 @@ static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len, struct flchip *chip = &lpddr->chips[chipnum]; int ret = 0; - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); ret = get_chip(map, chip, FL_READY); if (ret) { - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -528,7 +527,7 @@ static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len, *retlen = len; put_chip(map, chip); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -568,9 +567,9 @@ static int lpddr_point(struct mtd_info *mtd, loff_t adr, size_t len, else thislen = len; /* get the chip */ - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); ret = get_chip(map, chip, FL_POINT); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); if (ret) break; @@ -610,7 +609,7 @@ static void lpddr_unpoint (struct mtd_info *mtd, loff_t adr, size_t len) else thislen = len; - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); if (chip->state == FL_POINT) { chip->ref_point_counter--; if (chip->ref_point_counter == 0) @@ -620,7 +619,7 @@ static void lpddr_unpoint (struct mtd_info *mtd, loff_t adr, size_t len) "pointed region\n", map->name); put_chip(map, chip); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); len -= thislen; ofs = 0; @@ -726,10 +725,10 @@ int do_xxlock(struct mtd_info *mtd, loff_t adr, uint32_t len, int thunk) int chipnum = adr >> lpddr->chipshift; struct flchip *chip = &lpddr->chips[chipnum]; - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); ret = get_chip(map, chip, FL_LOCKING); if (ret) { - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -749,7 +748,7 @@ int do_xxlock(struct mtd_info *mtd, loff_t adr, uint32_t len, int thunk) goto out; } out: put_chip(map, chip); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -770,10 +769,10 @@ int word_program(struct map_info *map, loff_t adr, uint32_t curval) int chipnum = adr >> lpddr->chipshift; struct flchip *chip = &lpddr->chips[chipnum]; - spin_lock(chip->mutex); + mutex_lock(&chip->mutex); ret = get_chip(map, chip, FL_WRITING); if (ret) { - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } @@ -787,7 +786,7 @@ int word_program(struct map_info *map, loff_t adr, uint32_t curval) } out: put_chip(map, chip); - spin_unlock(chip->mutex); + mutex_unlock(&chip->mutex); return ret; } -- cgit v1.2.3 From 8ae664184c45def51ff0b61d4bd6c6671db6cb4f Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Thu, 5 Aug 2010 09:19:26 +0200 Subject: mtd: change struct flchip_shared spinlock locking into mutex This patch prevent to schedule while atomic by changing the flchip_shared spinlock into a mutex. This should be save since no atomic path will use this lock. It was suggested by Arnd Bergmann and Vasiliy Kulikov. Signed-off-by: Stefani Seibold Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/lpddr/lpddr_cmds.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'drivers/mtd/lpddr/lpddr_cmds.c') diff --git a/drivers/mtd/lpddr/lpddr_cmds.c b/drivers/mtd/lpddr/lpddr_cmds.c index fece5be58715..04fdfcca93f7 100644 --- a/drivers/mtd/lpddr/lpddr_cmds.c +++ b/drivers/mtd/lpddr/lpddr_cmds.c @@ -98,7 +98,7 @@ struct mtd_info *lpddr_cmdset(struct map_info *map) numchips = lpddr->numchips / lpddr->qinfo->HWPartsNum; for (i = 0; i < numchips; i++) { shared[i].writing = shared[i].erasing = NULL; - spin_lock_init(&shared[i].lock); + mutex_init(&shared[i].lock); for (j = 0; j < lpddr->qinfo->HWPartsNum; j++) { *chip = lpddr->chips[i]; chip->start += j << lpddr->chipshift; @@ -217,7 +217,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) */ struct flchip_shared *shared = chip->priv; struct flchip *contender; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); contender = shared->writing; if (contender && contender != chip) { /* @@ -230,7 +230,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) * get_chip returns success we're clear to go ahead. */ ret = mutex_trylock(&contender->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); if (!ret) goto retry; mutex_unlock(&chip->mutex); @@ -245,7 +245,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) mutex_unlock(&contender->mutex); return ret; } - spin_lock(&shared->lock); + mutex_lock(&shared->lock); /* We should not own chip if it is already in FL_SYNCING * state. Put contender and retry. */ @@ -261,7 +261,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) Must sleep in such a case. */ if (mode == FL_ERASING && shared->erasing && shared->erasing->oldstate == FL_ERASING) { - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); @@ -275,7 +275,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) shared->writing = chip; if (mode == FL_ERASING) shared->erasing = chip; - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } ret = chip_ready(map, chip, mode); @@ -348,7 +348,7 @@ static void put_chip(struct map_info *map, struct flchip *chip) { if (chip->priv) { struct flchip_shared *shared = chip->priv; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); if (shared->writing == chip && chip->oldstate == FL_READY) { /* We own the ability to write, but we're done */ shared->writing = shared->erasing; @@ -356,7 +356,7 @@ static void put_chip(struct map_info *map, struct flchip *chip) /* give back the ownership */ struct flchip *loaner = shared->writing; mutex_lock(&loaner->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); mutex_unlock(&chip->mutex); put_chip(map, loaner); mutex_lock(&chip->mutex); @@ -374,11 +374,11 @@ static void put_chip(struct map_info *map, struct flchip *chip) * Don't let the switch below mess things up since * we don't have ownership to resume anything. */ - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); wake_up(&chip->wq); return; } - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } switch (chip->oldstate) { -- cgit v1.2.3