| Message ID | 20231127123933.48851-1-wxjstz@126.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | lib: sbi: Improve sbi_hsm_hart_interruptible_mask | expand |
On Mon, Nov 27, 2023 at 6:10 PM Xiang W <wxjstz@126.com> wrote: > > Improve bit scanning with for_each_set_bit. > > Signed-off-by: Xiang W <wxjstz@126.com> > --- > lib/sbi/sbi_hsm.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/lib/sbi/sbi_hsm.c b/lib/sbi/sbi_hsm.c > index 147f954..bffac27 100644 > --- a/lib/sbi/sbi_hsm.c > +++ b/lib/sbi/sbi_hsm.c > @@ -114,22 +114,18 @@ int sbi_hsm_hart_interruptible_mask(const struct sbi_domain *dom, > ulong hbase, ulong *out_hmask) > { > int hstate; > - ulong i, hmask, dmask; > + ulong i, dmask; > > *out_hmask = 0; > if (!sbi_hartid_valid(hbase)) > return SBI_EINVAL; > > dmask = sbi_domain_get_assigned_hartmask(dom, hbase); > - for (i = 0; i < BITS_PER_LONG; i++) { > - hmask = 1UL << i; > - if (!(dmask & hmask)) > - continue; > - > + for_each_set_bit(i, &dmask, BITS_PER_LONG) { We have intentionally avoided using for_each_set_bit() here because for_each_set_bit() is quite heavy handed and involves function calls to find_first_bit() and find_next_bit. The for_each_set_bitbetter for dealing with large bitmaps but for small bitmaps it becomes an overkill. Also, please keep in mind that sbi_hsm_hart_interruptible_mask() is in hot-path because it is called by sbi_ipi_send_many(). > hstate = __sbi_hsm_hart_get_state(hbase + i); > if (hstate == SBI_HSM_STATE_STARTED || > hstate == SBI_HSM_STATE_SUSPENDED) > - *out_hmask |= hmask; > + *out_hmask |= 1UL << i; > } > > return 0; > -- > 2.42.0 > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi Regards, Anup
diff --git a/lib/sbi/sbi_hsm.c b/lib/sbi/sbi_hsm.c index 147f954..bffac27 100644 --- a/lib/sbi/sbi_hsm.c +++ b/lib/sbi/sbi_hsm.c @@ -114,22 +114,18 @@ int sbi_hsm_hart_interruptible_mask(const struct sbi_domain *dom, ulong hbase, ulong *out_hmask) { int hstate; - ulong i, hmask, dmask; + ulong i, dmask; *out_hmask = 0; if (!sbi_hartid_valid(hbase)) return SBI_EINVAL; dmask = sbi_domain_get_assigned_hartmask(dom, hbase); - for (i = 0; i < BITS_PER_LONG; i++) { - hmask = 1UL << i; - if (!(dmask & hmask)) - continue; - + for_each_set_bit(i, &dmask, BITS_PER_LONG) { hstate = __sbi_hsm_hart_get_state(hbase + i); if (hstate == SBI_HSM_STATE_STARTED || hstate == SBI_HSM_STATE_SUSPENDED) - *out_hmask |= hmask; + *out_hmask |= 1UL << i; } return 0;
Improve bit scanning with for_each_set_bit. Signed-off-by: Xiang W <wxjstz@126.com> --- lib/sbi/sbi_hsm.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)