replace KM_LARGE with explicit vmalloc use
Alex Elder
aelder at sgi.com
Thu Jan 21 13:06:21 CST 2010
Christoph Hellwig wrote:
> We use the KM_LARGE flag to make kmem_alloc and friends use vmalloc if
> nessecary. As we only need this for a few boot/mount time allocations
> just switch to explicit vmalloc calls there.
I like this. Simplifies kmalloc for everybody...
> Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Alex Elder <aelder at sgi.com>
> Index: xfs/fs/xfs/linux-2.6/kmem.c
> ===================================================================
> --- xfs.orig/fs/xfs/linux-2.6/kmem.c 2010-01-17 13:33:52.749254562 +0100
> +++ xfs/fs/xfs/linux-2.6/kmem.c 2010-01-17 21:07:10.919003863 +0100
> @@ -16,7 +16,6 @@
> * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> */
> #include <linux/mm.h>
> -#include <linux/vmalloc.h>
> #include <linux/highmem.h>
> #include <linux/swap.h>
> #include <linux/blkdev.h>
> @@ -24,8 +23,25 @@
> #include "time.h"
> #include "kmem.h"
>
> -#define MAX_VMALLOCS 6
> -#define MAX_SLAB_SIZE 0x20000
> +/*
> + * Greedy allocation. May fail and may return vmalloced memory.
> + *
> + * Must be freed using kmem_free_large.
> + */
> +void *
> +kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
> +{
> + void *ptr;
> + size_t kmsize = maxsize;
> +
> + while (!(ptr = kmem_zalloc_large(kmsize))) {
> + if ((kmsize >>= 1) <= minsize)
> + kmsize = minsize;
> + }
> + if (ptr)
> + *size = kmsize;
> + return ptr;
> +}
>
> void *
> kmem_alloc(size_t size, unsigned int __nocast flags)
> @@ -34,19 +50,8 @@ kmem_alloc(size_t size, unsigned int __n
> gfp_t lflags = kmem_flags_convert(flags);
> void *ptr;
>
> -#ifdef DEBUG
> - if (unlikely(!(flags & KM_LARGE) && (size > PAGE_SIZE))) {
> - printk(KERN_WARNING "Large %s attempt, size=%ld\n",
> - __func__, (long)size);
> - dump_stack();
> - }
> -#endif
> -
> do {
> - if (size < MAX_SLAB_SIZE || retries > MAX_VMALLOCS)
> - ptr = kmalloc(size, lflags);
> - else
> - ptr = __vmalloc(size, lflags, PAGE_KERNEL);
> + ptr = kmalloc(size, lflags);
> if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
> return ptr;
> if (!(++retries % 100))
> @@ -68,27 +73,6 @@ kmem_zalloc(size_t size, unsigned int __
> return ptr;
> }
>
> -void *
> -kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize,
> - unsigned int __nocast flags)
> -{
> - void *ptr;
> - size_t kmsize = maxsize;
> - unsigned int kmflags = (flags & ~KM_SLEEP) | KM_NOSLEEP;
> -
> - while (!(ptr = kmem_zalloc(kmsize, kmflags))) {
> - if ((kmsize <= minsize) && (flags & KM_NOSLEEP))
> - break;
> - if ((kmsize >>= 1) <= minsize) {
> - kmsize = minsize;
> - kmflags = flags;
> - }
> - }
> - if (ptr)
> - *size = kmsize;
> - return ptr;
> -}
> -
> void
> kmem_free(const void *ptr)
> {
> Index: xfs/fs/xfs/linux-2.6/kmem.h
> ===================================================================
> --- xfs.orig/fs/xfs/linux-2.6/kmem.h 2010-01-17 13:33:52.755254557 +0100
> +++ xfs/fs/xfs/linux-2.6/kmem.h 2010-01-17 21:07:10.919003863 +0100
> @@ -21,6 +21,7 @@
> #include <linux/slab.h>
> #include <linux/sched.h>
> #include <linux/mm.h>
> +#include <linux/vmalloc.h>
>
> /*
> * General memory allocation interfaces
> @@ -30,7 +31,6 @@
> #define KM_NOSLEEP 0x0002u
> #define KM_NOFS 0x0004u
> #define KM_MAYFAIL 0x0008u
> -#define KM_LARGE 0x0010u
>
> /*
> * We use a special process flag to avoid recursive callbacks into
> @@ -42,7 +42,7 @@ kmem_flags_convert(unsigned int __nocast
> {
> gfp_t lflags;
>
> - BUG_ON(flags & ~(KM_SLEEP|KM_NOSLEEP|KM_NOFS|KM_MAYFAIL|KM_LARGE));
> + BUG_ON(flags & ~(KM_SLEEP|KM_NOSLEEP|KM_NOFS|KM_MAYFAIL));
>
> if (flags & KM_NOSLEEP) {
> lflags = GFP_ATOMIC | __GFP_NOWARN;
> @@ -56,10 +56,25 @@ kmem_flags_convert(unsigned int __nocast
>
> extern void *kmem_alloc(size_t, unsigned int __nocast);
> extern void *kmem_zalloc(size_t, unsigned int __nocast);
> -extern void *kmem_zalloc_greedy(size_t *, size_t, size_t, unsigned int __nocast);
> extern void *kmem_realloc(const void *, size_t, size_t, unsigned int __nocast);
> extern void kmem_free(const void *);
>
> +static inline void *kmem_zalloc_large(size_t size)
> +{
> + void *ptr;
> +
> + ptr = vmalloc(size);
> + if (ptr)
> + memset(ptr, 0, size);
> + return ptr;
> +}
> +static inline void kmem_free_large(void *ptr)
> +{
> + vfree(ptr);
> +}
> +
> +extern void *kmem_zalloc_greedy(size_t *, size_t, size_t);
> +
> /*
> * Zone interfaces
> */
> Index: xfs/fs/xfs/quota/xfs_qm.c
> ===================================================================
> --- xfs.orig/fs/xfs/quota/xfs_qm.c 2010-01-17 13:33:52.767254546 +0100
> +++ xfs/fs/xfs/quota/xfs_qm.c 2010-01-17 21:07:10.921003908 +0100
> @@ -118,9 +118,14 @@ xfs_Gqm_init(void)
> */
> udqhash = kmem_zalloc_greedy(&hsize,
> XFS_QM_HASHSIZE_LOW * sizeof(xfs_dqhash_t),
> - XFS_QM_HASHSIZE_HIGH * sizeof(xfs_dqhash_t),
> - KM_SLEEP | KM_MAYFAIL | KM_LARGE);
> - gdqhash = kmem_zalloc(hsize, KM_SLEEP | KM_LARGE);
> + XFS_QM_HASHSIZE_HIGH * sizeof(xfs_dqhash_t));
> + if (!udqhash)
> + goto out;
> +
> + gdqhash = kmem_zalloc_large(hsize);
> + if (!udqhash)
> + goto out_free_udqhash;
> +
> hsize /= sizeof(xfs_dqhash_t);
> ndquot = hsize << 8;
>
> @@ -170,6 +175,11 @@ xfs_Gqm_init(void)
> mutex_init(&qcheck_lock);
> #endif
> return xqm;
> +
> + out_free_udqhash:
> + kmem_free_large(udqhash);
> + out:
> + return NULL;
> }
>
> /*
> @@ -189,8 +199,8 @@ xfs_qm_destroy(
> xfs_qm_list_destroy(&(xqm->qm_usr_dqhtable[i]));
> xfs_qm_list_destroy(&(xqm->qm_grp_dqhtable[i]));
> }
> - kmem_free(xqm->qm_usr_dqhtable);
> - kmem_free(xqm->qm_grp_dqhtable);
> + kmem_free_large(xqm->qm_usr_dqhtable);
> + kmem_free_large(xqm->qm_grp_dqhtable);
> xqm->qm_usr_dqhtable = NULL;
> xqm->qm_grp_dqhtable = NULL;
> xqm->qm_dqhashmask = 0;
> @@ -219,8 +229,12 @@ xfs_qm_hold_quotafs_ref(
> */
> mutex_lock(&xfs_Gqm_lock);
>
> - if (xfs_Gqm == NULL)
> + if (!xfs_Gqm) {
> xfs_Gqm = xfs_Gqm_init();
> + if (!xfs_Gqm)
> + return ENOMEM;
> + }
> +
> /*
> * We can keep a list of all filesystems with quotas mounted for
> * debugging and statistical purposes, but ...
> Index: xfs/fs/xfs/xfs_itable.c
> ===================================================================
> --- xfs.orig/fs/xfs/xfs_itable.c 2010-01-17 13:33:52.778254478 +0100
> +++ xfs/fs/xfs/xfs_itable.c 2010-01-17 21:07:10.922012487 +0100
> @@ -408,8 +408,10 @@ xfs_bulkstat(
> (XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog);
> nimask = ~(nicluster - 1);
> nbcluster = nicluster >> mp->m_sb.sb_inopblog;
> - irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4,
> - KM_SLEEP | KM_MAYFAIL | KM_LARGE);
> + irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4);
> + if (!irbuf)
> + return ENOMEM;
> +
> nirbuf = irbsize / sizeof(*irbuf);
>
> /*
> @@ -727,7 +729,7 @@ xfs_bulkstat(
> /*
> * Done, we're either out of filesystem or space to put the data.
> */
> - kmem_free(irbuf);
> + kmem_free_large(irbuf);
> *ubcountp = ubelem;
> /*
> * Found some inodes, return them now and return the error next time.
> Index: xfs/fs/xfs/linux-2.6/xfs_buf.c
> ===================================================================
> --- xfs.orig/fs/xfs/linux-2.6/xfs_buf.c 2010-01-17 15:06:01.607003933 +0100
> +++ xfs/fs/xfs/linux-2.6/xfs_buf.c 2010-01-17 21:07:10.924003662 +0100
> @@ -1525,8 +1525,8 @@ xfs_alloc_bufhash(
>
> btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */
> btp->bt_hashmask = (1 << btp->bt_hashshift) - 1;
> - btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) *
> - sizeof(xfs_bufhash_t), KM_SLEEP | KM_LARGE);
> + btp->bt_hash = kmem_zalloc_large((1 << btp->bt_hashshift) *
> + sizeof(xfs_bufhash_t));
> for (i = 0; i < (1 << btp->bt_hashshift); i++) {
> spin_lock_init(&btp->bt_hash[i].bh_lock);
> INIT_LIST_HEAD(&btp->bt_hash[i].bh_list);
> @@ -1537,7 +1537,7 @@ STATIC void
> xfs_free_bufhash(
> xfs_buftarg_t *btp)
> {
> - kmem_free(btp->bt_hash);
> + kmem_free_large(btp->bt_hash);
> btp->bt_hash = NULL;
> }
>
>
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