Patch for sd.c to reduce maximum kmalloc size
Marcelo,
I think the attached patch is ready to be included in a -preX. The only voice of dissent I received was from a guy who obviously was confused about relative sizes of vmalloc and kmalloc areas.
Note that I am introducing a couple of XXXes. They mark places which I think are buggy, but I do not want to fix them right away and thus to hinder the more important fix in this patch. These places were there for months, and nobody complained. If 2.4.19 does not eat scsi disks, I'll return to these two with a mallet in 2.4.20 time.
Greetings,
-- Pete
drivers/scsi/sd.c +59 -45
@@ -65,8 +65,13 @@* static const char RCSid[] = "$Header:"; */ +/* system major --> sd_gendisks index */ +#define SD_MAJOR_IDX (i) (MAJOR(i) & SD_MAJOR_MASK) +/* sd_gendisks index --> system major */ #define SD_MAJOR (i) (!(i) ? SCSI_DISK0_MAJOR : SCSI_DISK1_MAJOR-1+(i)) +#define SD_PARTITION (dev) ((SD_MAJOR_IDX(dev) << 8) | (MINOR(dev) & 255)) +#define SCSI_DISKS_PER_MAJOR 16#define SD_MAJOR_NUMBER (i) SD_MAJOR((i) >> 8)#define SD_MINOR_NUMBER (i) ((i) & 255)
@@ -84,9 +89,8 @@#define SD_TIMEOUT (30 * HZ)#define SD_MOD_TIMEOUT (75 * HZ) -struct hd_struct *sd; -static Scsi_Disk *rscsi_disks; +static struct gendisk *sd_gendisks;static int *sd_sizes;static int *sd_blocksizes;static int *sd_hardsizes;/* Hardware sector size */
@@ -195,7 +199,9 @@if (put_user (diskinfo[0 ], &loc->heads) ||put_user (diskinfo[1 ], &loc->sectors) ||put_user (diskinfo[2 ], &loc->cylinders) || -put_user (sd[SD_PARTITION (inode->i_rdev)].start_sect, &loc->start)) +put_user (sd_gendisks[SD_MAJOR_IDX ( + inode->i_rdev)].part[MINOR ( + inode->i_rdev)].start_sect, &loc->start))return -EFAULT ;return 0 ; }
@@ -226,7 +232,9 @@if (put_user (diskinfo[0 ], &loc->heads) ||put_user (diskinfo[1 ], &loc->sectors) ||put_user (diskinfo[2 ], (unsigned int *) &loc->cylinders) || -put_user (sd[SD_PARTITION (inode->i_rdev)].start_sect, &loc->start)) +put_user (sd_gendisks[SD_MAJOR_IDX ( + inode->i_rdev)].part[MINOR ( + inode->i_rdev)].start_sect, &loc->start))return -EFAULT ;return 0 ; }
@@ -286,30 +294,32 @@static int sd_init_command (Scsi_Cmnd * SCpnt) { -int dev, devm, block, this_count; +int dev, block, this_count; +struct hd_struct *ppnt;Scsi_Disk *dpnt;#if CONFIG_SCSI_LOGGING char nbuff[6 ];#endif - devm =SD_PARTITION (SCpnt->request.rq_dev); + ppnt = &sd_gendisks[SD_MAJOR_IDX (SCpnt->request.rq_dev)].part[MINOR (SCpnt->request.rq_dev)]; dev =DEVICE_NR (SCpnt->request.rq_dev); block = SCpnt->request.sector; this_count = SCpnt->request_bufflen >>9 ; -SCSI_LOG_HLQUEUE (1 ,printk ("Doing sd request, dev = %d, block = %d\n" , devm, block)); +SCSI_LOG_HLQUEUE (1 ,printk ("Doing sd request, dev = 0x%x, block = %d\n" , + SCpnt->request.rq_dev, block)); dpnt = &rscsi_disks[dev]; -if (devm >= (sd_template.dev_max <<4 ) || +if (dev >= sd_template.dev_max || !dpnt->device || !dpnt->device->online || - block + SCpnt->request.nr_sectors > sd[devm].nr_sects) { + block + SCpnt->request.nr_sectors > ppnt->nr_sects) {SCSI_LOG_HLQUEUE (2 ,printk ("Finishing %ld sectors\n" , SCpnt->request.nr_sectors));SCSI_LOG_HLQUEUE (2 ,printk ("Retry with 0x%p\n" , SCpnt));return 0 ; } - block += sd[devm].start_sect; + block += ppnt->start_sect;if (dpnt->device->changed) {/* * quietly refuse to do anything to a changed disc until the changed
@@ -318,7 +328,7 @@/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */ return 0 ; } -SCSI_LOG_HLQUEUE (2 ,sd_devname (devm, nbuff)); +SCSI_LOG_HLQUEUE (2 ,sd_devname (dev, nbuff));SCSI_LOG_HLQUEUE (2 ,printk ("%s : real dev = /dev/%d, block = %d\n" , nbuff, dev, block));
@@ -576,8 +586,6 @@ fops: &sd_fops, }; -static struct gendisk *sd_gendisks = &sd_gendisk; -#define SD_GENDISK (i) sd_gendisks[(i) / SCSI_DISKS_PER_MAJOR]/*
@@ -644,7 +652,9 @@default :break ; } - error_sector -= sd[SD_PARTITION (SCpnt->request.rq_dev)].start_sect; + error_sector -= sd_gendisks[SD_MAJOR_IDX ( + SCpnt->request.rq_dev)].part[MINOR ( + SCpnt->request.rq_dev)].start_sect; error_sector &= ~(block_sectors -1 ); good_sectors = error_sector - SCpnt->request.sector;if (good_sectors <0 || good_sectors >= this_count)
@@ -1146,23 +1156,12 @@ hardsect_size[SD_MAJOR (i)] = sd_hardsizes + i * (SCSI_DISKS_PER_MAJOR <<4 ); max_sectors[SD_MAJOR (i)] = sd_max_sectors + i * (SCSI_DISKS_PER_MAJOR <<4 ); } -/* -* FIXME: should unregister blksize_size, hardsect_size and max_sectors when -* the module is unloaded. -*/ - sd =kmalloc ((sd_template.dev_max <<4 ) * -sizeof (struct hd_struct ), -GFP_ATOMIC ); -if (!sd) - goto cleanup_sd; -memset (sd,0 , (sd_template.dev_max <<4 ) *sizeof (struct hd_struct )); - -if (N_USED_SD_MAJORS >1 ) - sd_gendisks =kmalloc (N_USED_SD_MAJORS *sizeof (struct gendisk ),GFP_ATOMIC ); -if (!sd_gendisks) - goto cleanup_sd_gendisks; + + sd_gendisks =kmalloc (N_USED_SD_MAJORS *sizeof (struct gendisk ),GFP_ATOMIC ); +if (!sd_gendisks) + goto cleanup_sd_gendisks;for (i =0 ; i <N_USED_SD_MAJORS ; i++) { - sd_gendisks[i] = sd_gendisk; + sd_gendisks[i] = sd_gendisk;/* memcpy */ sd_gendisks[i].de_arr =kmalloc (SCSI_DISKS_PER_MAJOR *sizeof *sd_gendisks[i].de_arr,GFP_ATOMIC );if (!sd_gendisks[i].de_arr)
@@ -1179,7 +1178,11 @@ sd_gendisks[i].major_name ="sd" ; sd_gendisks[i].minor_shift =4 ; sd_gendisks[i].max_p =1 <<4 ; - sd_gendisks[i].part = sd + (i *SCSI_DISKS_PER_MAJOR <<4 ); + sd_gendisks[i].part =kmalloc ((SCSI_DISKS_PER_MAJOR <<4 ) *sizeof (struct hd_struct ), +GFP_ATOMIC ); +if (!sd_gendisks[i].part) + goto cleanup_gendisks_part; +memset (sd_gendisks[i].part,0 , (SCSI_DISKS_PER_MAJOR <<4 ) *sizeof (struct hd_struct )); sd_gendisks[i].sizes = sd_sizes + (i *SCSI_DISKS_PER_MAJOR <<4 ); sd_gendisks[i].nr_real =0 ; sd_gendisks[i].real_devices =
@@ -1188,18 +1191,19 @@return 0 ; +cleanup_gendisks_part: +kfree (sd_gendisks[i].flags); cleanup_gendisks_flags:kfree (sd_gendisks[i].de_arr); cleanup_gendisks_de_arr:while (--i >=0 ) {kfree (sd_gendisks[i].de_arr);kfree (sd_gendisks[i].flags); +kfree (sd_gendisks[i].part); } -if (sd_gendisks != &sd_gendisk) -kfree (sd_gendisks); +kfree (sd_gendisks); + sd_gendisks =NULL ; cleanup_sd_gendisks: -kfree (sd); -cleanup_sd:kfree (sd_max_sectors); cleanup_max_sectors:kfree (sd_hardsizes);
@@ -1320,6 +1324,7 @@*/ int revalidate_scsidisk (kdev_t dev,int maxusage) { +struct gendisk *sdgd;int target;int max_p;int start;
@@ -1333,14 +1338,15 @@ }DEVICE_BUSY =1 ; - max_p = sd_gendisks->max_p; - start = target << sd_gendisks->minor_shift; + sdgd = &SD_GENDISK (target); + max_p = sd_gendisk.max_p; + start = target << sd_gendisk.minor_shift;for (i = max_p -1 ; i >=0 ; i--) {int index = start + i;invalidate_device (MKDEV_SD_PARTITION (index),1 ); - sd_gendisks->part[index].start_sect =0 ; - sd_gendisks->part[index].nr_sects =0 ; + sdgd->part[SD_MINOR_NUMBER (index)].start_sect =0 ; + sdgd->part[SD_MINOR_NUMBER (index)].nr_sects =0 ;/* * Reset the blocksize for everything so that we can read * the partition table. Technically we will determine the
@@ -1372,6 +1378,7 @@static void sd_detach (Scsi_Device * SDp) {Scsi_Disk *dpnt; +struct gendisk *sdgd;int i, j;int max_p;int start;
@@ -1384,17 +1391,18 @@/* If we are disconnecting a disk driver, sync and invalidate * everything */ + sdgd = &SD_GENDISK (i); max_p = sd_gendisk.max_p; start = i << sd_gendisk.minor_shift;for (j = max_p -1 ; j >=0 ; j--) {int index = start + j;invalidate_device (MKDEV_SD_PARTITION (index),1 ); - sd_gendisks->part[index].start_sect =0 ; - sd_gendisks->part[index].nr_sects =0 ; + sdgd->part[SD_MINOR_NUMBER (index)].start_sect =0 ; + sdgd->part[SD_MINOR_NUMBER (index)].nr_sects =0 ; sd_sizes[index] =0 ; } -devfs_register_partitions (&SD_GENDISK (i), +devfs_register_partitions (sdgd,SD_MINOR_NUMBER (start),1 );/* unregister_disk() */ dpnt->has_part_table =0 ;
@@ -1430,16 +1438,22 @@kfree (sd_sizes);kfree (sd_blocksizes);kfree (sd_hardsizes); -kfree ((char *) sd); +for (i =0 ; i <N_USED_SD_MAJORS ; i++) { +#if 0 /* XXX aren't we forgetting to deallocate something? */ +kfree (sd_gendisks[i].de_arr); +kfree (sd_gendisks[i].flags); +#endif +kfree (sd_gendisks[i].part); + } }for (i =0 ; i <N_USED_SD_MAJORS ; i++) {del_gendisk (&sd_gendisks[i]); - blk_size[SD_MAJOR (i)] =NULL ; + blk_size[SD_MAJOR (i)] =NULL ;/* XXX blksize_size actually? */ hardsect_size[SD_MAJOR (i)] =NULL ; read_ahead[SD_MAJOR (i)] =0 ; } sd_template.dev_max =0 ; -if (sd_gendisks != &sd_gendisk) +if (sd_gendisks !=NULL )/* kfree tests for 0, but leave explicit */ kfree (sd_gendisks); }
drivers/scsi/sd.h +0 -3
@@ -23,8 +23,6 @@#include <linux/genhd.h> #endif -extern struct hd_struct *sd; - typedef struct scsi_disk { unsigned capacity; /* size in blocks */ Scsi_Device *device;
@@ -45,7 +43,6 @@#define N_SD_MAJORS 8#define SD_MAJOR_MASK (N_SD_MAJORS - 1) -#define SD_PARTITION (i) (((MAJOR(i) & SD_MAJOR_MASK) << 8) | (MINOR(i) & 255))#endif
kernel instruction level tracing
i'm trying to analyze netfiltering and routing workload inside the kernel for PowerPC(a typical kernel 'application', and I can not figure out how to do the workload analysis in use space for them), is there a way to trace all the instruction flow(e.g. a packet coming-in--> going-out) so I can use the result to further analyze things like cache hit/miss, latency,drop rate,etc? I'd like to collect the raw instruction flow in simulation state(non realtime).
LTT(Linux Trace Toolkit) is a good tool, but I want more detailing tracing info. I tried UML, it doesn't work well on PowerPC so far.
Is it possible at all?
Thanks
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